Update pythonpackage.yml

Author: martinspetlik

.github/workflows/pythonpackage.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:      
       matrix:
-        python-version: [3.10, 3.12]
+        python-version: ["3.10", "3.12"]
 
     steps:
     - uses: actions/checkout@v2