chore(deps): update docker/build-push-action action to v6 (main) (#11608)

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

Author: renovate[bot]

.github/workflows/publish-petclinic-benchmark-image.yml

@@ -29,7 +29,7 @@ jobs:
         run: echo "TS=$(date +'%Y%m%d%H%M%S')" >> $GITHUB_ENV
 
       - name: Push to GitHub packages
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           push: true
           file: benchmark-overhead/Dockerfile-petclinic-base