Update test matrix

Author: nikmolnar

.github/workflows/python-package.yml

@@ -19,7 +19,7 @@ jobs:
 
     strategy:
       matrix:
-        python-version: [2.7, 3.6, 3.7, 3.8, 3.9]
+        python-version: [3.9, '3.10', '3.11', '3.12']
 
     steps:
     - uses: actions/checkout@v2