Issue #28480: Adjust or skip tests if multithreading is disabled

Lib/test/test_asyncgen.py

-import asyncio
 import inspect
 import sys
 import types
@@ -6,6 +5,9 @@ import unittest
 
 from unittest import mock
 
+from test.support import import_module
+asyncio = import_module("asyncio")
+
 
 class AwaitException(Exception):
     pass

Lib/test/test_logging.py

@@ -4304,7 +4304,7 @@ class MiscTestCase(unittest.TestCase):
                      'logProcesses', 'currentframe',
                      'PercentStyle', 'StrFormatStyle', 'StringTemplateStyle',
                      'Filterer', 'PlaceHolder', 'Manager', 'RootLogger',
-                     'root'}
+                     'root', 'threading'}
         support.check__all__(self, logging, blacklist=blacklist)