Description of problem:

Product teams are allowed to prune images in stage that were already shipped to production indexes. This workflow should be forbidden.

E.g.

bare-metal-event-relay.v4.12.0 build released in

https://errata.devel.redhat.com/advisory/101291

got pruned in the v4.12 stage index after the push of 

https://errata.devel.redhat.com/advisory/108542 (to stage)

Pub task: https://errata.devel.redhat.com/push/push_results/402719

See CLOUDDST-17379 comments for details.

Version-Release number of selected component (if applicable): not applicable

How reproducible: always

Steps to Reproduce: Steps described in CLOUDDST-17379 comments.

Actual results: 

The image that was previously released in prod gets pruned in stage after the succesful push and replaced with the new one.

bare-metal-event-relay.v4.12.1 

Expected results:

After the push from the advisory (https://pub.devel.redhat.com/pub/task/602197/), the images should be either listed both in the index, or the push should fail on opm error.

bare-metal-event-relay.v4.12.0
bare-metal-event-relay.v4.12.1

Additional info: none