Bump ruby/setup-ruby from 1.219.0 to 1.221.0 (#248)

Bumps [ruby/setup-ruby](https://github.com/ruby/setup-ruby) from 1.219.0 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](ruby/setup-ruby@f2f42b7...32110d4)

---
updated-dependencies:
- dependency-name: ruby/setup-ruby
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
       - name: Update .ruby-version with matrix value
         run: echo "${{ matrix.ruby_version }}" >| .ruby-version
       - name: Set up Ruby
-        uses: ruby/setup-ruby@f2f42b7848feff522ffa488a5236ba0a73bccbdd
+        uses: ruby/setup-ruby@32110d4e311bd8996b2a82bf2a43b714ccc91777
         with:
           bundler-cache: true
       - name: Run tests