chore(deps): update docker/metadata-action action to v6

Author: renovate[bot]

.github/workflows/build.yml

@@ -60,7 +60,7 @@ jobs:
         name: Docker metadata
         id: meta
         if: env.exists == 'false'
-        uses: docker/metadata-action@v5
+        uses: docker/metadata-action@v6
         with:
           context: git
           images: |