Update the ruby version in CI

Author: yugui

.github/workflows/ruby.yml

@@ -14,7 +14,7 @@ jobs:
     name: Test
     strategy:
       matrix:
-        ruby-version: ['2.7', '3.0', '3.1', '3.2']
+        ruby-version: ['3.0', '3.1', '3.2', '3.3']
         os: ['ubuntu-latest', 'macos-latest']
     runs-on: ${{ matrix.os }}