build(deps): bump fastify/github-action-merge-dependabot

Bumps [fastify/github-action-merge-dependabot](https://github.com/fastify/github-action-merge-dependabot) from 2.5.0 to 2.6.0.
- [Release notes](https://github.com/fastify/github-action-merge-dependabot/releases)
- [Commits](fastify/github-action-merge-dependabot@v2.5.0...v2.6.0)

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

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

.github/workflows/tests.yml

@@ -28,7 +28,7 @@ jobs:
     needs: test
     runs-on: ubuntu-latest
     steps:
-      - uses: fastify/github-action-merge-dependabot@v2.5.0
+      - uses: fastify/github-action-merge-dependabot@v2.6.0
         if: ${{ github.actor == 'dependabot[bot]' && github.event_name == 'pull_request' && contains(github.head_ref, 'dependabot/github_actions') }}
         with:
           github-token: ${{secrets.github_token}}