updated action with python 3.11

.github/workflows/python-app.yml

@@ -16,7 +16,7 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: Set up Python 3.9
+    - name: Set up Python 3.11
       uses: actions/setup-python@v2
       with:
         python-version: 3.9