fix lint issue

Author: LindaSummer

Lib/test/test_defaultdict.py

@@ -186,25 +186,25 @@ def test_union(self):
 
         with self.assertRaises(TypeError):
             i |= None
-            
+
     def test_default_race(self):
         cv = Condition()
         key = "default_race_key"
-        
+
         def default_factory(cv: Condition, cv_flag: list[bool]):
             with cv:
                 while not cv_flag[0]:
                     cv.wait()
                 return "default_value"
         ready_flag = [False]
         test_dict = defaultdict(lambda: default_factory(cv, ready_flag))
-        
+
         def writer(cv: Condition, cv_flag: list[bool], race_dict: dict):
             with cv:
                 race_dict[key] = "writer_value"
                 cv_flag[0] = True
                 cv.notify()
-        
+
         default_factory_thread = Thread(target=lambda: test_dict[key])
         writer_thread = Thread(target=lambda: writer(cv, ready_flag, test_dict))
         default_factory_thread.start()