build(deps): bump docker/build-push-action from 6.7.0 to 6.8.0

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 6.7.0 to 6.8.0.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v6.7.0...v6.8.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/ghcr-image-build-and-publish.yml

@@ -61,7 +61,7 @@ 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@v6.7.0
+        uses: docker/build-push-action@v6.8.0
         with:
           context: .
           platforms: linux/amd64,linux/arm64