add ruby 3.4.0 test

Author: kuboon

.github/workflows/main.yml

@@ -17,6 +17,7 @@ jobs:
           - '3.1.4'
           - '3.2.3'
           - '3.3.0'
+          - '3.4.0'
     steps:
     - uses: actions/checkout@v4
     - name: Set up Ruby