Bump docker/metadata-action from 5 to 6 in /.github/workflows

Bumps [docker/metadata-action](https://github.com/docker/metadata-action) from 5 to 6.
- [Release notes](https://github.com/docker/metadata-action/releases)
- [Commits](https://github.com/docker/metadata-action/compare/v5...v6)

---
updated-dependencies:
- dependency-name: docker/metadata-action
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/docker-release.yml

@@ -49,7 +49,7 @@ jobs:
 
       - name: Generate Docker image metadata
         id: docker-meta
-        uses: docker/metadata-action@v5
+        uses: docker/metadata-action@v6
         with:
           images: |
             ${{ secrets.DOCKERHUB_USERNAME }}/${{ secrets.DOCKERHUB_REPO }}

.github/workflows/docker.yml

@@ -51,7 +51,7 @@ jobs:
 
       - name: Generate Docker image metadata
         id: docker-meta
-        uses: docker/metadata-action@v5
+        uses: docker/metadata-action@v6
         # Defaults:
         #     DOCKERHUB_USERNAME  : voc0der
         #     DOCKERHUB_REPO      : youtubedl-material