Backfill migration for LMSGroupSet

[marcospri]

For:

• Store group sets in their own table #6834

After storing new group sets in #6837 we'll backfill thet new table based on information from Grouping.extra

Testing

• Start configuring an assignment with groups. We record the group sets the moment we list them in the creation screen, no need to to finish the configuration process.

For example:

https://hypothesis.instructure.com/courses/125/assignments/7412/edit?name=Assignment%20creation%20-%20test%20&due_at=&points_possible=0

• Remove the rows on the new table

truncate lms_group_set;

• Run the migration

tox -e dev --run-command 'alembic upgrade head'     
dev run-test-pre: PYTHONHASHSEED='2142052960'
dev run-test-pre: commands[0] | pip-sync-faster requirements/dev.txt --pip-args --disable-pip-version-check
dev run-test: commands[0] | alembic upgrade head
INFO  [alembic.runtime.migration] Context impl PostgresqlImpl.
INFO  [alembic.runtime.migration] Will assume transactional DDL.
INFO  [alembic.runtime.migration] Running upgrade 4b813a44a6c9 -> ba295703738b, Backfill LMSGroupSet

• Check the rows in lms_group_set have been created based on the information in grouping:

select * from lms_group_set;
 id | lms_id |               name               | lms_course_id |          created           |          updated           
----+--------+----------------------------------+---------------+----------------------------+----------------------------
 29 | 121    | Test group set                   |           105 | 2024-11-05 08:43:51.641694 | 2024-11-05 08:43:51.641694
 30 | 122    | Empty group set                  |           105 | 2024-11-05 08:43:51.641694 | 2024-11-05 08:43:51.641694
 31 | 125    | PoC                              |           105 | 2024-11-05 08:43:51.641694 | 2024-11-05 08:43:51.641694
 32 | 129    | Group Set with No Students in It |           105 | 2024-11-05 08:43:51.641694 | 2024-11-05 08:43:51.641694
 33 | 389    | everyone                         |           105 | 2024-11-05 08:43:51.641694 | 2024-11-05 08:43:51.641694
(5 rows)

[marcospri]

Fix more of these flaky tests.