Add 'updated_at' column to subscriptions table

This removes the explicit ownership change on `set_updated_at()`.

This line assumes the existence of user `postgres` (which does not in my case). It will be owned by the user that creates it and that is fine.

Author: JWDobken

packages/sync-engine/src/database/migrations/0012_add_updated_at.sql

@@ -8,8 +8,6 @@ begin
 end;
 $$;
 
-alter function set_updated_at() owner to postgres;
-
 alter table stripe.subscriptions
     add updated_at timestamptz default timezone('utc'::text, now()) not null;