Bump ruby/setup-ruby from 1.305.0 to 1.308.0

Bumps [ruby/setup-ruby](https://github.com/ruby/setup-ruby) from 1.305.0 to 1.308.0.
- [Release notes](https://github.com/ruby/setup-ruby/releases)
- [Changelog](https://github.com/ruby/setup-ruby/blob/master/release.rb)
- [Commits](ruby/setup-ruby@0cb964f...97ecb7b)

---
updated-dependencies:
- dependency-name: ruby/setup-ruby
  dependency-version: 1.308.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -55,7 +55,7 @@ jobs:
         with:
           ref: ${{ inputs.ref || github.ref }}
           show-progress: false
-      - uses: ruby/setup-ruby@0cb964fd540e0a24c900370abf38a33466142735 # v1.305.0
+      - uses: ruby/setup-ruby@97ecb7b512899eb71ab1bf2310a624c6f1589ac6 # v1.308.0
         with:
           bundler-cache: true
       - name: Setup Redis