DNF and bootc in Image Mode Fedora variants

See: https://fedoraproject.org/wiki/Changes/DNFAndBootcInImageModeFedora

BZ: https://bugzilla.redhat.com/show_bug.cgi?id=2293627

Changes in current variants

• Fedora CoreOS: Ready
  • https://github.com/coreos/fedora-coreos-tracker/issues/1687
  • https://github.com/coreos/fedora-coreos-config/pull/2915
• Atomic Desktops:
  • https://pagure.io/workstation-ostree-config/pull-request/514
  • Kinoite:
    • https://pagure.io/fedora-kde/SIG/issue/519
    • https://pagure.io/workstation-ostree-config/pull-request/545
  • Pending https://pagure.io/releng/issue/12142 to be available in official images
  • Pushed to rawhide images in ci-test repo: https://gitlab.com/fedora/ostree/ci-test
• IoT:
  • https://github.com/fedora-iot/iot-distro/issues/51
  • https://pagure.io/fedora-iot/ostree/pull-request/54