ci: Bump dependabot/fetch-metadata from 2 to 3

Bumps [dependabot/fetch-metadata](https://github.com/dependabot/fetch-metadata) from 2 to 3.
- [Release notes](https://github.com/dependabot/fetch-metadata/releases)
- [Commits](dependabot/fetch-metadata@v2...v3)

---
updated-dependencies:
- dependency-name: dependabot/fetch-metadata
  dependency-version: '3'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/dependabot-auto-merge.yaml

@@ -13,7 +13,7 @@ jobs:
     if: github.actor == 'dependabot[bot]'
     runs-on: ubuntu-24.04
     steps:
-      - uses: dependabot/fetch-metadata@v2
+      - uses: dependabot/fetch-metadata@v3
         id: metadata
 
       - name: Generate app token