Refactor test utilities and enhance ASGI settings

- Cleaned up and standardized assertions in ApiTestMixin for API response validation.
- Updated ASGI settings to use os.environ for setting the DJANGO_SETTINGS_MODULE.
- Removed unused imports and improved formatting in settings.py.
- Refactored URL patterns in urls.py for better readability and organization.
- Enhanced view functions in views.py for consistency and clarity.
- Added .flake8 configuration for linting and style enforcement.
- Introduced type stubs for django-environ to improve type checking with Pylance.

parks/views_update.py

@@ -9,7 +9,7 @@ def prepare_changes_data(self, cleaned_data):
     if data.get("closing_date"):
         data["closing_date"] = data["closing_date"].isoformat()
     # Convert Decimal fields to strings
-    decimal_fields = ['latitude', 'longitude', 'size_acres', 'average_rating']
+    decimal_fields = ["latitude", "longitude", "size_acres", "average_rating"]
     for field in decimal_fields:
         if data.get(field):
             data[field] = str(data[field])