Remove the updated_at

[orta]

When I looked at the logs, there were a lot of

2023-07-23T14:08:12.318106+00:00 heroku[router]: at=info method=POST path="/webhook/hooks/trunk/d286a7388ab9bddfdf5cb79300094e4d1f241b14" host=cocoapods-metadata-service.herokuapp.com request_id=49be6b42-4603-4557-bcd6-aa045d6abe2f fwd="34.229.86.1" dyno=web.1 connect=0ms service=11ms status=200 bytes=217 protocol=https
2023-07-23T14:08:12.904645+00:00 app[web.1]: [MobilliumToolTips - 0.1.0] Getting info on README, CHANGELOG and community metrics.Uncaught error: error: column "updated_at" is of type timestamp without time zone but expression is of type text

This removes the updated_at column - it's marked as nullable in the db, and it's not something we show anywhere