One of the things we do during the tests is change the config. But that's global state and different tests were interfering.
E.g. one test would set `clear_config([:instance, :admin_privileges], [:statuses_read])`, but while that runs, another test may
do `clear_config([:instance, :admin_privileges], [:user_invite])`. Now the code for the first test checks the setting, and it
finds `:user_invite` instead of `:statuses_read`.
Now the modules where this happens are marked to run synchronously, so they don't interfere with each other.
In general, tests that match these criteria can be made async:
- Doesn't use real Cachex.
- Doesn't write to the Config / Application Environment.
- Uses Mock. Using Mox is fine.
- Uses the streamer.
