Change warnings module import in ctypes._layout to lazy

Author: jonathandung

Lib/ctypes/_layout.py

@@ -5,11 +5,12 @@
 """
 
 import sys
-import warnings
 
 from _ctypes import CField, buffer_info
 import ctypes
 
+lazy import warnings
+
 def round_down(n, multiple):
     assert n >= 0
     assert multiple > 0