chore(deps): bump docker/metadata-action from 5.5.1 to 5.6.1 (#61)

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](https://github.com/docker/metadata-action/compare/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] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/publish.yml

@@ -17,7 +17,7 @@ jobs:
         uses: actions/checkout@v4
       - name: Prepare
         id: prep
-        uses: docker/metadata-action@v5.5.1
+        uses: docker/metadata-action@v5.6.1
         with:
           images: |
             ${{ github.repository_owner }}/mediawiki-ldap