bpo-41139: Deprecate `cgi.log()` (GH-25625)

diff --git a/Lib/test/test_cgi.py b/Lib/test/test_cgi.py
index 239d975..c1b893d 100644
--- a/Lib/test/test_cgi.py
+++ b/Lib/test/test_cgi.py
@@ -6,6 +6,7 @@
 from collections import namedtuple
 from io import StringIO, BytesIO
 from test import support
+from test.support import warnings_helper
 
 class HackedSysModule:
     # The regression test will have real values in sys.argv, which
@@ -220,6 +221,7 @@ def test_separator(self):
                     else:
                         self.assertEqual(fs.getvalue(key), expect_val[0])
 
+    @warnings_helper.ignore_warnings(category=DeprecationWarning)
     def test_log(self):
         cgi.log("Testing")