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] <support@github.com>

Author: dependabot[bot]

.github/workflows/docker.yml

@@ -45,7 +45,7 @@ jobs:
             type=raw,value=${{ matrix.ROS_DISTRO }}-${{ github.job }}
 
       - name: Build and push Docker image
-        uses: docker/build-push-action@v6.7.0
+        uses: docker/build-push-action@v6.8.0
         with:
           context: .
           file: .docker/Dockerfile
@@ -86,7 +86,7 @@ jobs:
             type=raw,value=${{ matrix.ROS_DISTRO }}-${{ github.job }}
 
       - name: Build and push Docker image
-        uses: docker/build-push-action@v6.7.0
+        uses: docker/build-push-action@v6.8.0
         with:
           context: .
           file: .docker/Dockerfile