Update docker/metadata-action action to v6 (#124)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/release.yml

@@ -19,7 +19,7 @@ jobs:
           registry: ghcr.io
           username: ${{github.actor}}
           password: ${{secrets.GITHUB_TOKEN}}
-      - uses: docker/metadata-action@v5.10.0
+      - uses: docker/metadata-action@v6
         id: meta
         with:
           images: ghcr.io/cego/swarm-app