This container can be pulled via:
  docker pull registry.opensuse.org/devel/bci/sle-15-sp4/images/bci/bci-micro:15.4
  docker pull registry.opensuse.org/devel/bci/sle-15-sp4/images/bci/bci-micro:15.4.116.2

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.