[github-actions]: Bump dependabot/fetch-metadata in /.github/workflows (aws#326)

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>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

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

@@ -19,7 +19,7 @@ jobs:
     steps:
       - name: Fetch Dependabot metadata
         id: metadata
-        uses: dependabot/fetch-metadata@v2
+        uses: dependabot/fetch-metadata@v3
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}