I maintain the RubyGems, Bundler and the standard libraries of the Ruby language. So, I've been extract many of the standard libraries to default gems and GitHub at Ruby 3.0. But the some of libraries still remains in only Ruby repository. I will describe these situation.
So, Rubyists can submit a pull-request for the default gems like net-http, irb or etc after Ruby 3.0. We need to learn about the mechanism of the default gems. and also learn the bundled gems. I will describe a technic for developing the standard libraries with GitHub..