Add ruby v3.4 support

Author: mmassaki

.github/workflows/actions.yml

@@ -16,6 +16,7 @@ jobs:
         ruby-version:
           - '3.2'
           - '3.3'
+          - '3.4'
     steps:
       - uses: zendesk/checkout@v3
       - uses: zendesk/setup-ruby@v1