ruby 3.5 is not compatible with rubocop

Author: jvmvik

.github/workflows/ci.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby: ['2.7.8', '3.1.0','head'] # test only recommend Ruby version (and stable version on the GitHub action server)
+        ruby: ['2.7.8', '3.1.0','3.4.4'] # test only recommend Ruby version (and stable version on the GitHub action server)
     steps:
       - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1