[Test] Execute container registry post deployment migration on an environment

Problem statement

With the CI pipeline for executing Container Registry post deployment migrations (PDM) ready for use, we would like to run a test by executing a PDM on an environment like pre or staging. Container registry migrations appear to be quite rare, so it seems unlikely that we will get an opportunity to test this organically.

We want to test the new automation for executing Container Registry post deployment migrations (PDMs) with an actual post deployment migration. The migration itself can be a no-op, since we only need to check that the migration is actually executed.

If there is a real post deployment migration available (not a no-op), we can use that as well. This will allow us to do a more complete test, but is not required.