Remove organization_user_aliases table

The following discussion from !191575 (merged) should be addressed:

  • @l.rosa started a discussion: (+2 comments)

    I don't think dropping the table in the same milestone is a safe approach. It can be a problem for zero-downtime upgrades. It seems we still have to have some traffic going on in the table:

    image

    (source)

    Table activity could be due to FK cascade deletes or from a query somewhere in the app. As we can't know for sure, I recommend deleting the table in the next milestone.

In the next milestone we should remove the organization_user_aliases table and associated Organizations::OrganizationUserAlias model.