Bump docker/metadata-action from 4.0.1 to 5.5.1

Bumps [docker/metadata-action](https://github.com/docker/metadata-action) from 4.0.1 to 5.5.1.
- [Release notes](https://github.com/docker/metadata-action/releases)
- [Upgrade guide](https://github.com/docker/metadata-action/blob/master/UPGRADE.md)
- [Commits](docker/metadata-action@69f6fc9...8e5442c)

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

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

.github/workflows/docker-publish.yml

@@ -20,7 +20,7 @@ jobs:
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
-        uses: docker/metadata-action@69f6fc9d46f2f8bf0d5491e4aabe0bb8c6a4678a
+        uses: docker/metadata-action@8e5442c4ef9f78752691e2d8f8d19755c6f78e81
         with:
           images: alfg/nginx-rtmp