Update docker/metadata-action digest to a1a78f1

Author: renovate[bot]

.github/workflows/ci.yaml

@@ -87,7 +87,7 @@ jobs:
       - name: Extract Docker metadata
         id: meta
         timeout-minutes: 5
-        uses: docker/metadata-action@b53be03109c4ef6f6cc7aa545b84b17a7fe51c1e
+        uses: docker/metadata-action@a1a78f1e24dfe9c0feac5d30b1c09d7a790f26ed
         with:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
           tags: |