bpo-44498: suppress DeprecationWarnings for asynchat, asyncore and smtpd in tests (GH-26905) (GH-26907)

(cherry picked from commit 22e7effad571f8e524d2f71ff55bbf2a25306753)

Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>
diff --git a/Lib/test/test_asynchat.py b/Lib/test/test_asynchat.py
index b32eddd..973ac1f 100644
--- a/Lib/test/test_asynchat.py
+++ b/Lib/test/test_asynchat.py
@@ -4,8 +4,6 @@
 from test.support import socket_helper
 from test.support import threading_helper
 
-import asynchat
-import asyncore
 import errno
 import socket
 import sys
@@ -14,6 +12,12 @@
 import unittest
 import unittest.mock
 
+import warnings
+with warnings.catch_warnings():
+    warnings.simplefilter('ignore', DeprecationWarning)
+    import asynchat
+    import asyncore
+
 HOST = socket_helper.HOST
 SERVER_QUIT = b'QUIT\n'