Bump docker/build-push-action from 6.14.0 to 6.15.0

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 6.14.0 to 6.15.0.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](0adf995921...471d1dc4e0)

---
updated-dependencies:
- dependency-name: docker/build-push-action
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/docker-publish.yml

@@ -55,7 +55,7 @@ jobs:
       # Build and push Docker image with Buildx (don't push on PR)
       # https://github.com/docker/build-push-action
       - name: Build and push Docker image
-        uses: docker/build-push-action@0adf9959216b96bec444f325f1e493d4aa344497
+        uses: docker/build-push-action@471d1dc4e07e5cdedd4c2171150001c434f0b7a4
         with:
           context: .
           push: ${{ github.event_name != 'pull_request' }}