fix: linting issue

fastapi/routing.py

@@ -211,6 +211,7 @@ def get_request_handler(
     is_coroutine = (
         asyncio.iscoroutinefunction(dependant.call)
         or callable(dependant.call)
+        and hasattr(dependant.call, "__call__")
         and inspect.iscoroutinefunction(dependant.call.__call__)
     )
     is_body_form = body_field and isinstance(body_field.field_info, params.Form)