Update postgresqlreceiver vacuum metric unit to vacuum not vacuums (open-telemetry#43272)

Updating the unit of the metric `postgresql.table.vacuum.count` in
`postgresqlreceiver` to be `vacuum` instead of `vacuums`, to comply with
the semantic conventions.
<!-- Issue number (e.g. #1234) or full URL to issue, if applicable. -->
#### Link to tracking issue
Fixes:
[open-telemetry#43207](open-telemetry#43207)

<!--Describe what testing was performed and which tests were added.-->
#### Testing

<!--Describe the documentation added.-->
#### Documentation

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Author: beshbeeshy

.chloggen/postgresqlreceiver-vacuum-count-metric-unit.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. receiver/filelog)
+component: receiver/postgresql
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Change the unit of the metric `postgresql.table.vacuum.count` to be `vacuum` instead of vacuums"
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [43272]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

receiver/postgresqlreceiver/documentation.md

@@ -212,7 +212,7 @@ Number of times a table has manually been vacuumed.
 
 | Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic | Stability |
 | ---- | ----------- | ---------- | ----------------------- | --------- | --------- |
-| {vacuums} | Sum | Int | Cumulative | true | development |
+| {vacuum} | Sum | Int | Cumulative | true | development |
 
 ### postgresql.wal.age
 

receiver/postgresqlreceiver/internal/metadata/generated_metrics.go

@@ -477,7 +477,7 @@ metrics:
     stability:
       level: development
     enabled: true
-    unit: "{vacuums}"
+    unit: "{vacuum}"
     sum:
       aggregation_temporality: cumulative
       monotonic: true

receiver/postgresqlreceiver/internal/metadata/generated_metrics_test.go

@@ -798,7 +798,7 @@ resourceMetrics:
                   startTimeUnixNano: "1000000"
                   timeUnixNano: "2000000"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest
@@ -958,7 +958,7 @@ resourceMetrics:
                   startTimeUnixNano: "1000000"
                   timeUnixNano: "2000000"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest
@@ -1118,7 +1118,7 @@ resourceMetrics:
                   startTimeUnixNano: "1000000"
                   timeUnixNano: "2000000"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest
@@ -1278,7 +1278,7 @@ resourceMetrics:
                   startTimeUnixNano: "1000000"
                   timeUnixNano: "2000000"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest

receiver/postgresqlreceiver/metadata.yaml

@@ -312,7 +312,7 @@ resourceMetrics:
                   startTimeUnixNano: "1706802467703361527"
                   timeUnixNano: "1706802526712082422"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest
@@ -472,7 +472,7 @@ resourceMetrics:
                   startTimeUnixNano: "1706802467703361527"
                   timeUnixNano: "1706802526712082422"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest
@@ -857,7 +857,7 @@ resourceMetrics:
                   startTimeUnixNano: "1706802467703361527"
                   timeUnixNano: "1706802526712082422"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest
@@ -1017,7 +1017,7 @@ resourceMetrics:
                   startTimeUnixNano: "1706802467703361527"
                   timeUnixNano: "1706802526712082422"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest

receiver/postgresqlreceiver/testdata/integration/expected_all_db.yaml

@@ -801,7 +801,7 @@ resourceMetrics:
                   startTimeUnixNano: "1000000"
                   timeUnixNano: "2000000"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest
@@ -964,7 +964,7 @@ resourceMetrics:
                   startTimeUnixNano: "1000000"
                   timeUnixNano: "2000000"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest
@@ -1127,7 +1127,7 @@ resourceMetrics:
                   startTimeUnixNano: "1000000"
                   timeUnixNano: "2000000"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest
@@ -1290,7 +1290,7 @@ resourceMetrics:
                   startTimeUnixNano: "1000000"
                   timeUnixNano: "2000000"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest

receiver/postgresqlreceiver/testdata/integration/expected_all_db_connpool.yaml

@@ -641,7 +641,7 @@ resourceMetrics:
                   startTimeUnixNano: "1000000"
                   timeUnixNano: "2000000"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest
@@ -801,7 +801,7 @@ resourceMetrics:
                   startTimeUnixNano: "1000000"
                   timeUnixNano: "2000000"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest
@@ -961,7 +961,7 @@ resourceMetrics:
                   startTimeUnixNano: "1000000"
                   timeUnixNano: "2000000"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest
@@ -1121,7 +1121,7 @@ resourceMetrics:
                   startTimeUnixNano: "1000000"
                   timeUnixNano: "2000000"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest

receiver/postgresqlreceiver/testdata/integration/expected_all_db_schemaattr.yaml

@@ -155,7 +155,7 @@ resourceMetrics:
                   startTimeUnixNano: "1706802402706723341"
                   timeUnixNano: "1706802461712893428"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest
@@ -315,7 +315,7 @@ resourceMetrics:
                   startTimeUnixNano: "1706802402706723341"
                   timeUnixNano: "1706802461712893428"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest
@@ -700,7 +700,7 @@ resourceMetrics:
                   startTimeUnixNano: "1706802402706723341"
                   timeUnixNano: "1706802461712893428"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest
@@ -860,7 +860,7 @@ resourceMetrics:
                   startTimeUnixNano: "1706802402706723341"
                   timeUnixNano: "1706802461712893428"
               isMonotonic: true
-            unit: '{vacuums}'
+            unit: '{vacuum}'
         scope:
           name: github.com/open-telemetry/opentelemetry-collector-contrib/receiver/postgresqlreceiver
           version: latest