* Rails and Ruby versions follow the most recent to oldest, except for
Rails main, so we can keep the Gemfile the first one.
* Excluding specific matrix combinations based on the Gemfile first,
Ruby version next, and keep the same order (most recent -> oldest)
* Quote all Ruby versions to keep things consistent. It's required for
the '3.0' version to avoid the float issue where it'd use the latest
3.x instead.
Remove `ActiveSupport::Dependencies.reference`
This was deleted from Rails: 14d4edd7c3
As far as I can tell, it was meant to add a performance boost at some point in the past but doesn't seem to do anything useful these days.
Carlos Antonio da Silva