bpo-45128: fixes `test_multiprocessing_fork` mysterious crash (GH-28387)

(cherry picked from commit 1d42408495402b06ecae91420735aeff454be6b5)

Co-authored-by: Nikita Sobolev <mail@sobolevn.me>
diff --git a/Lib/test/test_logging.py b/Lib/test/test_logging.py
index c969a3f..8356e6b 100644
--- a/Lib/test/test_logging.py
+++ b/Lib/test/test_logging.py
@@ -4421,8 +4421,10 @@ def _extract_logrecord_process_name(key, logMultiprocessing, conn=None):
             name = mp.current_process().name
 
             r1 = logging.makeLogRecord({'msg': f'msg1_{key}'})
-            del sys.modules['multiprocessing']
-            r2 = logging.makeLogRecord({'msg': f'msg2_{key}'})
+
+            # https://bugs.python.org/issue45128
+            with support.swap_item(sys.modules, 'multiprocessing', None):
+                r2 = logging.makeLogRecord({'msg': f'msg2_{key}'})
 
             results = {'processName'  : name,
                        'r1.processName': r1.processName,
@@ -4471,7 +4473,6 @@ def test_multiprocessing(self):
             if multiprocessing_imported:
                 import multiprocessing
 
-
     def test_optional(self):
         r = logging.makeLogRecord({})
         NOT_NONE = self.assertIsNotNone