Add Ruby 3.3 to the CI test matrix

.github/workflows/test.yml

@@ -16,7 +16,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ["3.0", "3.1", "3.2"]
+        ruby: ["3.0", "3.1", "3.2", "3.3"]
     steps:
     - uses: actions/checkout@v3
     - uses: ruby/setup-ruby@v1