Update python-app.yml

Update to use pyproject.toml

Author: jirivrany

.github/workflows/python-app.yml

@@ -28,7 +28,8 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install flake8 pytest
-        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+        # Install the package in editable mode with dev dependencies
+        pip install -e .[dev]
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names