Update docker/build-push-action digest to ef6cba3

Author: renovate[bot]

Diff for: .github/workflows/docker-publish.yml

@@ -72,7 +72,7 @@ jobs:
       # https://github.com/docker/build-push-action
       - name: Build and push Docker image
         id: build-and-push
-        uses: docker/build-push-action@2a53c6ccda456d31fb62eedc658aae06e238b7bd
+        uses: docker/build-push-action@ef6cba335306ace1da064b44f9f739dec9be9fa0
         with:
           context: .
           push: ${{ github.event_name != 'pull_request' }}