extended python tests to run on recent python versions, too

.github/workflows/python-tests.yml

@@ -14,7 +14,7 @@ jobs:
     
     strategy:
       matrix:
-        python: [2.7, 3.5, 3.6, 3.7, 3.8]
+        python: [2.7, 3.5, 3.6, 3.7, 3.8, 3.9, 3.10, 3.11, 3.12]
         os: [ubuntu-latest, windows-latest, macOS-latest]
 
     steps: