This container can be pulled via:
  docker pull registry.opensuse.org/devel/bci/sle-15-sp3/images/bci/bci-micro:15.3
  docker pull registry.opensuse.org/devel/bci/sle-15-sp3/images/bci/bci-micro:15.3.22.6

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.