Cleanups for ostree repo related operations

[dustymabe]

Now that we are no longer delivering new updates via the OSTree repo we should be able to clean up various pieces of our code base:

• Any OSTree related steps from https://github.com/coreos/fedora-coreos-pipeline.git
• coreos-ostree-importer
  • The code at https://github.com/coreos/fedora-coreos-releng-automation/tree/main/coreos-ostree-importer
  • The definitions at:
    • https://pagure.io/fedora-infra/ansible/blob/main/f/playbooks/openshift-apps/coreos-ostree-importer.yml
    • https://pagure.io/fedora-infra/ansible/blob/main/f/roles/openshift-apps/coreos-ostree-importer
• robosign_ostree()
  • https://github.com/coreos/coreos-assembler/blob/d4327a4c70d09f23e51f7bf8e3d45268b8a18dff/src/cmd-sign#L124

[aaradhak]

Fedora-infra ansible PR merged - https://pagure.io/fedora-infra/ansible/pull-request/3043#

[aaradhak]

This issue got closed as one of the PRs commit message had Fixes: tag. Two more PRs are to pending be merged to close this issue, hence re-opened this tracker issue.