Merge pull request tmm1#230 from s4na/ruby3.3

Add Ruby 3.3 to CI

Author: tmm1

.github/workflows/ci.yml

@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [ ruby-head, '3.2', '3.1', '3.0', '2.7', truffleruby ]
+        ruby: [ ruby-head, '3.3','3.2', '3.1', '3.0', '2.7', truffleruby ]
     steps:
       - name: Checkout
         uses: actions/checkout@v2