Bump ruby/setup-ruby from 1.278.0 to 1.287.0 (#8482)

Bumps [ruby/setup-ruby](https://github.com/ruby/setup-ruby) from 1.278.0 to 1.287.0.
- [Release notes](https://github.com/ruby/setup-ruby/releases)
- [Changelog](https://github.com/ruby/setup-ruby/blob/master/release.rb)
- [Commits](https://github.com/ruby/setup-ruby/compare/4c24fa5ec04b2e79eb40571b1cee2a0d2b705771...8d27f39a5e7ad39aebbcbd1324f7af020229645c)

---
updated-dependencies:
- dependency-name: ruby/setup-ruby
  dependency-version: 1.287.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

.github/workflows/jekyll-gh-pages.yml

@@ -31,7 +31,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v6
       - name: Setup Ruby
-        uses: ruby/setup-ruby@4c24fa5ec04b2e79eb40571b1cee2a0d2b705771
+        uses: ruby/setup-ruby@8d27f39a5e7ad39aebbcbd1324f7af020229645c
         with:
           ruby-version: '3.2.3' # Not needed with a .ruby-version file
           bundler-cache: true # runs 'bundle install' and caches installed gems automatically