ci: pin docker/metadata-action to working version (#2924)

Pin docker/metadata-action to 5.4 until
https://github.com/docker/metadata-action/issues/381 is fixed

.github/workflows/container.yml

@@ -31,7 +31,11 @@ jobs:
           repository: libretime/libretime-${{ matrix.target }}
           readme-filepath: ./README.md
 
-      - uses: docker/metadata-action@v5
+      # This cannot be upgraded until we develop a workaround for medata-action
+      # appending cwd:// to the bake-file output. 5.5 is not compatible with
+      # upload-artifact
+      # https://github.com/docker/metadata-action/issues/381
+      - uses: docker/metadata-action@v5.4.0
         id: meta
         with:
           bake-target: ${{ matrix.target }}