Bumps [ruby/setup-ruby](https://github.com/ruby/setup-ruby) from 1.218.0 to 1.221.0.
- [Release notes](https://github.com/ruby/setup-ruby/releases)
- [Changelog](https://github.com/ruby/setup-ruby/blob/master/release.rb)
- [Commits](d781c1b4ed...32110d4e31)
---
updated-dependencies:
- dependency-name: ruby/setup-ruby
dependency-type: direct:production
update-type: version-update:semver-minor
...
Signed-off-by: dependabot[bot] <support@github.com>