insights: change oob migration deprecation version to 4.0
Created by: CristinaBirkel
Description
We can't deprecate in 3.34
because the new no-op migration was also introduced in that version and won't have had a chance to run yet. This causes the upgrade to fail because the migration is marked as 0% completed. So instead we'll deprecate in 4.0.
Test plan
This should unblock CI for the release cut. Ran it locally and confirmed: