Add Ruby 3.4 to test matrix

Author: mblumtritt

.github/workflows/test.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: [ruby-head, '3.3', '3.2', '3.1.2', '3.1', '3.0']
+        ruby-version: [ruby-head, '3.4', '3.3', '3.2', '3.1.2', '3.1', '3.0']
 
     steps:
     - uses: actions/checkout@v3