Updates GHA workflow to use Ruby to get a gem-based theme

Author: infews

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

@@ -28,6 +28,12 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+      - name: Setup Ruby
+        uses: ruby/setup-ruby
+        with:
+#          ruby-version: '3.3.6' # Not needed with a .ruby-version file
+          bundler-cache: true # runs 'bundle install' and caches installed gems automatically
+          cache-version: 0 # Increment this number if you need to re-download cached gems
       - name: Setup Pages
         uses: actions/configure-pages@v5
       - name: Build with Jekyll