[ci] Add hide-from-release-notes label to Dependabot PRs (#2828)

Author: joshlf

.github/dependabot.yml

@@ -12,6 +12,8 @@ updates:
     directory: /
     schedule:
       interval: daily
+    labels:
+      - "hide-from-release-notes"
     commit-message:
       # The trailing space instructs dependabot not to insert a colon between
       # the prefix and the rest of the message.