build(deps): bump fastify/github-action-merge-dependabot from 2.7.1 to 3

Bumps [fastify/github-action-merge-dependabot](https://github.com/fastify/github-action-merge-dependabot) from 2.7.1 to 3.
- [Release notes](https://github.com/fastify/github-action-merge-dependabot/releases)
- [Commits](fastify/github-action-merge-dependabot@v2.7.1...v3)

---
updated-dependencies:
- dependency-name: fastify/github-action-merge-dependabot
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/ci.yml

@@ -56,6 +56,6 @@ jobs:
     needs: test
     runs-on: ubuntu-latest
     steps:
-      - uses: fastify/github-action-merge-dependabot@v2.7.1
+      - uses: fastify/github-action-merge-dependabot@v3
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}