Update docker/build-push-action digest to 31ca4e5 (#357)

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

Author: renovate[bot]

.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@7e094594beda23fc8f21fa31049f4b203e51096b
+        uses: docker/build-push-action@31ca4e5d51253d7e4a2317bfe74699cbe3a398a9
         with:
           context: .
           push: ${{ github.event_name != 'pull_request' }}