Add Ruby 3.1 to CI

Author: bastelfreak

.github/workflows/test.yml

@@ -19,6 +19,7 @@ jobs:
           - ruby: '2.6'
           - ruby: '2.7'
           - ruby: '3.0'
+          - ruby: '3.1'
             coverage: 'yes'
     env:
       COVERAGE: ${{ matrix.coverage }}