Trying to delete a user record from our admin panel throws the following
error:

`update or delete on table "users" violates foreign key constraint
"access_tokens_user_id_fkey" on table "access_tokens"
Detail: Key (id)=(....) is still referenced from table "access_tokens".`

We need to add a cascade delete to the `access_tokens` table.

Release Notes:

- N/A