Use `ActiveSupport::EventedFileUpdateChecker`

[gabebw]

Adding this line to config/development.rb sped up load times from 230ms per CSS file(!) to about 0.6ms per CSS file:

config.file_watcher = ActiveSupport::EventedFileUpdateChecker

I'm honestly not sure why this isn't the Rails default.

[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 5 days.

[gabebw]

Ping

[stevepolitodesign]

@gabebw thank you for opening this issue. My only concern is that according to the Guides, ActiveSupport::EventedFileUpdateChecker depends on the listen gem. So, we'd need to bring in another dependency.