This container can be pulled via:
  docker pull registry.opensuse.org/home/dirkmueller/bci/cr/sle-15-sp6/images/bci/bci-busybox:15.6
  docker pull registry.opensuse.org/home/dirkmueller/bci/cr/sle-15-sp6/images/bci/bci-busybox:15.6.1.275

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.