This container can be pulled via:
  docker pull registry.opensuse.org/devel/bci/slcs/next/containerfile/alp/bci/openjdk:21
  docker pull registry.opensuse.org/devel/bci/slcs/next/containerfile/alp/bci/openjdk:21-3.256

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.