fix(ci): Specify Bundler 2.6.2 as per Gemfile.lock

Author: bits-bytes-nn

.github/workflows/jekyll.yml

@@ -26,6 +26,8 @@ jobs:
           ruby-version: '2.6.3'
           bundler-cache: true
           cache-version: 0
+      - name: Install specific Bundler version
+        run: gem install bundler:2.6.2
       - name: Setup Pages
         id: pages
         uses: actions/configure-pages@v5