- Sort of. It's not via Parlour, because I read the docs and all it says
about dynamically generating things is "of course it's better to do
that", no examples. I tried my best, but Bo's work on `attr.rb` was
mind-boggling.
- Instead, let's add a simple but functional generator script that I
actually understand, as an alternative to maintaining these RBI files
for dynamic methods manually, so that we can get rid of some use of
`srb rbi hidden-definitions` since that's deprecated.
- TODO: Run this script as part of `brew typecheck --update` so it gets
updated with all the other RBI files periodically.
- Follow up to PR 14651.
