Fix Python versions for tests

Author: nikmolnar

.github/workflows/python-tests.yml

@@ -11,7 +11,7 @@ jobs:
 
     strategy:
       matrix:
-        python-version: [3.8, 3.9, 3.10, 3.11]
+        python-version: [3.8, 3.9, '3.10', '3.11']
 
     steps:
       - uses: actions/checkout@v2