Bump ruby/setup-ruby from 1.276.0 to 1.279.0

Bumps [ruby/setup-ruby](https://github.com/ruby/setup-ruby) from 1.276.0 to 1.279.0.
- [Release notes](https://github.com/ruby/setup-ruby/releases)
- [Changelog](https://github.com/ruby/setup-ruby/blob/master/release.rb)
- [Commits](ruby/setup-ruby@ae195bb...b90be12)

---
updated-dependencies:
- dependency-name: ruby/setup-ruby
  dependency-version: 1.279.0
  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

@@ -68,7 +68,7 @@ jobs:
           token: ${{ secrets.GOVUK_CI_GITHUB_API_TOKEN }}
 
       - name: Setup Ruby
-        uses: ruby/setup-ruby@ae195bbe749a7cef685ac729197124a48305c1cb # v1.276.0
+        uses: ruby/setup-ruby@b90be12699fdfcbee4440c2bba85f6f460446bb0 # v1.279.0
         with:
           bundler-cache: true
         env: