Fix typo in exception message in multiprocessing.pool (#99900)

Author: 153957

Lib/multiprocessing/pool.py

@@ -696,7 +696,7 @@ def _terminate_pool(cls, taskqueue, inqueue, outqueue, pool, change_notifier,
 
         if (not result_handler.is_alive()) and (len(cache) != 0):
             raise AssertionError(
-                "Cannot have cache with result_hander not alive")
+                "Cannot have cache with result_handler not alive")
 
         result_handler._state = TERMINATE
         change_notifier.put(None)