build(deps): bump docker/build-push-action from 6.2.0 to 6.7.0

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 6.2.0 to 6.7.0.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@1556069...5cd11c3)

---
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/build-container.yml

@@ -39,7 +39,7 @@ jobs:
         with:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
       - name: Build and push Docker image
-        uses: docker/build-push-action@15560696de535e4014efeff63c48f16952e52dd1
+        uses: docker/build-push-action@5cd11c3a4ced054e52742c5fd54dca954e0edd85
         with:
           context: ./contrib/docker
           push: ${{ github.repository_owner == 'freifunk-gluon' && github.event_name == 'push' }}