Editing or deleting a custom role left warm IDB caches showing stale
embedded role details and permissions in the agent list, since the
account_user cache key only tracked custom_role_id on the account user.
Bump the account_user cache key from the custom role lifecycle so clients
refetch the agent list. The destroy bump is needed because dependent:
nullify updates account_users via update_all and skips their callbacks.
Shivam Mishra
68bd8290e5