fix _run_authentication creating the coroutine result twice

Author: eugenenelou

ninja/operation.py

@@ -207,7 +207,11 @@ def _run_authentication(self, request: HttpRequest) -> Optional[HttpResponse]:
                 if is_async_callable(callback) or getattr(callback, "is_async", False):
                     result = callback(request)
                     if inspect.iscoroutine(result):
-                        result = async_to_sync(callback)(request)
+
+                        async def await_result(cor):
+                            return await cor
+
+                        result = async_to_sync(await_result)(result)
                 else:
                     result = callback(request)
             except Exception as exc: