Update docker/metadata-action action to v6

.gitea/workflows/build.yaml

@@ -18,7 +18,7 @@ jobs:
 
       - name: Login to Container Registry
         if: ${{ gitea.event_name != 'pull_request' }}
-        uses: docker/login-action@v4
+        uses: docker/login-action@v3
         with:
           registry: docker.valverde.cloud
           username: ${{ secrets.DOCKER_REGISTRY_USERNAME }}
@@ -26,7 +26,7 @@ jobs:
 
       - name: Generate Docker metadata
         id: meta
-        uses: docker/metadata-action@v5
+        uses: docker/metadata-action@v6
         with:
           images: |
             docker.valverde.cloud/${{ gitea.repository }}