Bump ruby/setup-ruby from 1.267.0 to 1.268.0

Bumps [ruby/setup-ruby](https://github.com/ruby/setup-ruby) from 1.267.0 to 1.268.0.
- [Release notes](https://github.com/ruby/setup-ruby/releases)
- [Changelog](https://github.com/ruby/setup-ruby/blob/master/release.rb)
- [Commits](ruby/setup-ruby@d5126b9...8aeb6ff)

---
updated-dependencies:
- dependency-name: ruby/setup-ruby
  dependency-version: 1.268.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

.github/workflows/pages-gem.yml

@@ -14,7 +14,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v5
       - name: Setup Ruby
-        uses: ruby/setup-ruby@d5126b9b3579e429dd52e51e68624dda2e05be25 # v1.267.0
+        uses: ruby/setup-ruby@8aeb6ff8030dd539317f8e1769a044873b56ea71 # v1.268.0
         with:
           ruby-version: '3.3'
       - name: Build gem