build: Update python-app.yml

removed playground scripts from flake8 linting

.github/workflows/python-app.yml

@@ -31,7 +31,7 @@ jobs:
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names
-        flake8 --count --select=E9,F63,F7,F82 --show-source --statistics --extend-exclude .venv,run.py ./
+        flake8 --count --select=E9,F63,F7,F82 --show-source --statistics --extend-exclude .venv,playground*.py ./
         # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
         flake8 --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics --extend-ignore W291,W293,W391,E701 --extend-exclude .venv,__init__.py,docking ./src
 #TODO: write unit tests for src scripts