VerifiedTrackCohortRemoval

Steps needed to remove Verified Track Cohort code:

1. Review and merge 18974

2. Ensure that there are CourseUserGroupPartitionGroup records for the cohorts to be migrated

3. Generate a grade report for each course run before/after migration?

4. Run separate data import script (creates MigrateVerifiedTrackCohortsSettings for the course runs to migrate)

5. Notify course teams?

6. Run manage.py lms swap_from_auto_track_cohort

7. Remove code (PR tbd)