Update docker/build-push-action action to v6

Author: renovate[bot]

.github/workflows/build-docker.yaml

@@ -116,7 +116,7 @@ jobs:
 
       - name: Build and push
         id: docker_build
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v6
         with:
           context: .
           push: ${{ github.event_name != 'pull_request' }}