Update golang Docker tag to v1.25 (#13)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| golang | stage | minor | `1.24` -> `1.25` |

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Dockerfile

@@ -1,5 +1,5 @@
 # Build the urlshortener binary
-FROM golang:1.24 AS builder
+FROM golang:1.25 AS builder
 
 WORKDIR /workspace