Add ENV flag to disable partition creation in initializer
The following discussion from !35981 (merged) should be addressed:
This requires the DB to exist. It's called from an initializer which explicitly handles the case where the DB doesn't exist, but I wonder if we'd be better off with an environment variable to disable this in the initializer, and a feature flag check in the Sidekiq worker (outside of this code)?
That is more complicated, of course, but the two cases are also slightly different. And the initializer will only run once in the app's life cycle, so having an env var shouldn't be a huge problem there