Bump ruby/setup-ruby from 1.302.0 to 1.304.0

Bumps [ruby/setup-ruby](https://github.com/ruby/setup-ruby) from 1.302.0 to 1.304.0.
- [Release notes](https://github.com/ruby/setup-ruby/releases)
- [Changelog](https://github.com/ruby/setup-ruby/blob/master/release.rb)
- [Commits](ruby/setup-ruby@7372622...94e4d89)

---
updated-dependencies:
- dependency-name: ruby/setup-ruby
  dependency-version: 1.304.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/rspec.yml

@@ -33,7 +33,7 @@ jobs:
       - run: rm -f Gemfile.lock
       - run: rm -f .ruby-version
       - name: Set up Ruby
-        uses: ruby/setup-ruby@7372622e62b60b3cb750dcd2b9e32c247ffec26a # v1.302.0
+        uses: ruby/setup-ruby@94e4d89d3e6c1c7599e0210d114c5ffb23f1a866 # v1.304.0
         with:
           ruby-version: ${{ matrix.ruby }}
           rubygems: latest