Update docker/metadata-action digest to a64d048 (#36)

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

Author: renovate[bot]

.github/workflows/docker.yml

@@ -20,7 +20,7 @@ jobs:
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
-        uses: docker/metadata-action@f7b4ed12385588c3f9bc252f0a2b520d83b52d48
+        uses: docker/metadata-action@a64d0487d7069df33b279515d35d60fa80e2ea62
         with:
           images: clivern/badger