Bump ruby/setup-ruby from 1.269.0 to 1.270.0 (#249)

Bumps [ruby/setup-ruby](https://github.com/ruby/setup-ruby) from 1.269.0 to 1.270.0.
- [Release notes](https://github.com/ruby/setup-ruby/releases)
- [Changelog](https://github.com/ruby/setup-ruby/blob/master/release.rb)
- [Commits](ruby/setup-ruby@d697be2...ac793fd)

---
updated-dependencies:
- dependency-name: ruby/setup-ruby
  dependency-version: 1.270.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

.github/workflows/lint-markdown.yaml

@@ -37,7 +37,7 @@ jobs:
 
       - name: Set up Ruby
         # See https://github.com/ruby/setup-ruby#versioning
-        uses: ruby/setup-ruby@d697be2f83c6234b20877c3b5eac7a7f342f0d0c  # v1.269.0
+        uses: ruby/setup-ruby@ac793fdd38cc468a4dd57246fa9d0e868aba9085  # v1.270.0
         with:
           ruby-version: 3.0