run mdl with Ruby 4

Author: faisal

.github/workflows/main.yml

@@ -157,7 +157,7 @@ jobs:
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: '3.4'
+          ruby-version: '4.0'
           bundler-cache: true
           cache-version: 1
         continue-on-error: ${{ matrix.experimental }}