remove the darwin workaround for parallel tests (#1412)

manage.py

@@ -1,55 +1,32 @@
 #!/usr/bin/env python
+"""Django's command-line utility for administrative tasks."""
 import os
 import sys
 
-if __name__ == "__main__":
+
+def main():
+    """Run administrative tasks."""
     try:
         command = sys.argv[1]
     except IndexError:
         command = "help"
 
     if command == "test":
         os.environ.setdefault("DJANGO_SETTINGS_MODULE", "config.settings.test")
-        # TODO: remove in django 4.1+
-        # patched for darwin
-        # https://adamj.eu/tech/2020/07/21/how-to-use-djangos-parallel-testing-on-macos-with-python-3.8-plus/
-        if sys.platform == "darwin":  # pragma: no cover
-            import multiprocessing
-
-            if os.environ.get("OBJC_DISABLE_INITIALIZE_FORK_SAFETY", "") != "YES":
-                print(
-                    (
-                        "Set OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES in your"
-                        + " environment to work around use of forking in Django's"
-                        + " test runner."
-                    ),
-                    file=sys.stderr,
-                )
-                sys.exit(1)
-            multiprocessing.set_start_method("fork")
     else:
         os.environ.setdefault("DJANGO_SETTINGS_MODULE", "config.settings.local")
 
     try:
         from django.core.management import execute_from_command_line
-    except ImportError:
-        # The above import may fail for some other reason. Ensure that the
-        # issue is really that Django is missing to avoid masking other
-        # exceptions on Python 2.
-        try:
-            import django  # noqa
-        except ImportError:
-            raise ImportError(
-                "Couldn't import Django. Are you sure it's installed and "
-                "available on your PYTHONPATH environment variable? Did you "
-                "forget to activate a virtual environment?"
-            )
+    except ImportError as exc:
+        raise ImportError(
+            "Couldn't import Django. Are you sure it's installed and "
+            "available on your PYTHONPATH environment variable? Did you "
+            "forget to activate a virtual environment?"
+        ) from exc
 
-        raise
+    execute_from_command_line(sys.argv)
 
-    # This allows easy placement of apps within the interior
-    # care directory.
-    current_path = os.path.dirname(os.path.abspath(__file__))
-    sys.path.append(os.path.join(current_path, "care"))
 
-    execute_from_command_line(sys.argv)
+if __name__ == "__main__":
+    main()