use 4 for func test

Author: KazuCocoa

.github/workflows/functional-test.yml

@@ -100,7 +100,7 @@ jobs:
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
       with:
-        ruby-version: 3.2
+        ruby-version: 4.0
     - name: Install dependencies
       run: bundle install