Merge branch 'main' into glitch-soc/merge-upstream

Conflicts:
- `app/controllers/home_controller.rb`:
  Upstream made it so `/web` is available to non-logged-in users
  and `/` redirects to `/web` instead of `/about`.
  Kept our version since glitch-soc's WebUI doesn't have what's
  needed yet and I think /about is still a much better landing
  page anyway.
- `app/models/form/admin_settings.rb`:
  Upstream added new settings, and glitch-soc had an extra setting.
  Not really a conflict.
  Added upstream's new settings.
- `app/serializers/initial_state_serializer.rb`:
  Upstream added a new `server` initial state object.
  Not really a conflict.
  Merged upstream's changes.
- `app/views/admin/settings/edit.html.haml`:
  Upstream added new settings.
  Not really a conflict.
  Merged upstream's changes.
- `app/workers/scheduler/feed_cleanup_scheduler.rb`:
  Upstream refactored that part and removed the file.
  Ported our relevant changes into `app/lib/vacuum/feeds_vacuum.rb`
- `config/settings.yml`:
  Upstream added new settings.
  Not a real conflict.
  Added upstream's new settings.

lib/tasks/mastodon.rake

@@ -11,7 +11,7 @@ namespace :mastodon do
     # When the application code gets loaded, it runs `lib/mastodon/redis_configuration.rb`.
     # This happens before application environment configuration and sets REDIS_URL etc.
     # These variables are then used even when REDIS_HOST etc. are changed, so clear them
-    # out so they don't interfer with our new configuration.
+    # out so they don't interfere with our new configuration.
     ENV.delete('REDIS_URL')
     ENV.delete('CACHE_REDIS_URL')
     ENV.delete('SIDEKIQ_REDIS_URL')