[3.10] Fix typos in the Lib directory (GH-28775) (GH-28804)

Fix typos in the Lib directory as identified by codespell.

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>.
(cherry picked from commit 745c9d9dfc1ad6fdfdf1d07420c6273ff67fa5be)

Co-authored-by: Christian Clauss <cclauss@me.com>
diff --git a/Lib/test/test_weakref.py b/Lib/test/test_weakref.py
index 5a3e59c..096833d 100644
--- a/Lib/test/test_weakref.py
+++ b/Lib/test/test_weakref.py
@@ -1472,7 +1472,7 @@ def check_weak_del_and_len_while_iterating(self, dict, testcontext):
         o = Object(123456)
         with testcontext():
             n = len(dict)
-            # Since underlaying dict is ordered, first item is popped
+            # Since underlying dict is ordered, first item is popped
             dict.pop(next(dict.keys()))
             self.assertEqual(len(dict), n - 1)
             dict[o] = o