Update docker/metadata-action action to v6

Author: renovate[bot]

.github/workflows/docker.yaml

@@ -30,7 +30,7 @@ jobs:
 
       - name: Docker meta
         id: meta
-        uses: docker/metadata-action@v5
+        uses: docker/metadata-action@v6
         with:
           # list of Docker images to use as base name for tags
           images: |