Fix setup-ruby compatibility

Author: marceltaeumel

.github/workflows/jekyll.yml

@@ -26,12 +26,12 @@ concurrency:
 jobs:
   # Build job
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Checkout
         uses: actions/checkout@v5
       - name: Setup Ruby
-        uses: ruby/setup-ruby@0a29871fe2b0200a17a4497bae54fe5df0d973aa # v1.115.3
+        uses: ruby/setup-ruby@v1
         with:
           ruby-version: '3.0' # Not needed with a .ruby-version file
           bundler-cache: true # runs 'bundle install' and caches installed gems automatically