Description of problem:
trust and trust_role tables are never archived (shadow or not) and there're no supported mechanism to clean those:

MariaDB [keystone]> delete from trust_role where trust_id in (select id from trust where deleted_at is not null);
Query OK, 3950918 rows affected (18.978 sec)

MariaDB [keystone]> delete from trust where deleted_at is not null;
Query OK, 1975401 rows affected (46.569 sec)

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1.
2.
3.

Actual results:

Expected results:

Additional info: