Add Ruby 3.3 to test matrix.

Author: alexreisner

.github/workflows/default.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ['2.7', '3.0', '3.1', '3.2']
+        ruby-version: ['2.7', '3.0', '3.1', '3.2', '3.3']
     steps:
     - uses: actions/checkout@v3
     - name: Set up Ruby