If you chose to use the rollback migration feature on your current version for example, you should still have a way to migrate, being that you are still on a supported migration path.
Rather than have it checked only as part of gitlab:db:configure, we will instead have it as a pre-req for every db:migrate command
Set the mininum supported migration version to be the schema version as of 11.11.0, and errors you if that is not detected during gitlab:db:configure