Drop Ruby 2.7 and add Ruby 3.3 for Ruby Tests in CI

Author: marcoroth

.github/workflows/tests.yml

@@ -39,7 +39,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: [2.7, '3.0', 3.1, 3.2]
+        ruby-version: ['3.0', 3.1, 3.2, 3.3]
 
     steps:
       - uses: actions/checkout@v3