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/querysets.py

@@ -1,17 +1,17 @@
 from django.db.models import QuerySet, Count, Q
 from .models import Park
 
+
 def get_base_park_queryset() -> QuerySet[Park]:
     """Get base queryset with all needed annotations and prefetches"""
     return (
-        Park.objects.select_related('operator', 'property_owner', 'location')
-        .prefetch_related(
-            'photos',
-            'rides'
-        )
+        Park.objects.select_related("operator", "property_owner", "location")
+        .prefetch_related("photos", "rides")
         .annotate(
-            current_ride_count=Count('rides', distinct=True),
-            current_coaster_count=Count('rides', filter=Q(rides__category="RC"), distinct=True)
+            current_ride_count=Count("rides", distinct=True),
+            current_coaster_count=Count(
+                "rides", filter=Q(rides__category="RC"), distinct=True
+            ),
         )
-        .order_by('name')
-    )
+        .order_by("name")
+    )