after pulp3 migration, docker schema v1 tags that haven't been migrated should be deleted
talking with the pulp3 team, pulp will not migrated v1 schema tags if there is a 'same named' v2 schema tag. The reason is that it generates them on the fly when a client requests them. Also pulp3 cannot have two tags (v1 and v2) with the same name in the same repository version.
So after migration during switchover we need to delete any v1 tags that haven't been migrated.