This container can be pulled via:
  docker pull registry.opensuse.org/kernel/tools/images/sle_15_sp6/kbuild-gitlab:15.6
  docker pull registry.opensuse.org/kernel/tools/images/sle_15_sp6/kbuild-gitlab:15.6.16.15
  docker pull registry.opensuse.org/kernel/tools/images/sle_15_sp6/kbuild-gitlab:latest

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.