chore: bump docker/metadata-action from 5.5.1 to 5.6.1 (#4841)

Bumps [docker/metadata-action](https://github.com/docker/metadata-action) from 5.5.1 to 5.6.1.
- [Release notes](https://github.com/docker/metadata-action/releases)
- [Commits](docker/metadata-action@v5.5.1...v5.6.1)

---
updated-dependencies:
- dependency-name: docker/metadata-action
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

.github/workflows/nightly-docker-build.yaml

@@ -52,7 +52,7 @@ jobs:
 
       - name: Extract Docker metadata
         id: meta
-        uses: docker/metadata-action@v5.5.1
+        uses: docker/metadata-action@v5.6.1
         with:
           images: ghcr.io/${{ github.repository }}:nightly