workflow: include time limit for testing to stop infinite loops

.github/workflows/python-app.yml

@@ -26,7 +26,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install flake8 pytest pyright
+        pip install flake8 pytest pytest-timeout pyright
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names