[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_time.py b/Lib/test/test_time.py
index db929bd..875615a 100644
--- a/Lib/test/test_time.py
+++ b/Lib/test/test_time.py
@@ -436,8 +436,8 @@ def test_mktime(self):
     @unittest.skipUnless(platform.libc_ver()[0] != 'glibc',
                          "disabled because of a bug in glibc. Issue #13309")
     def test_mktime_error(self):
-        # It may not be possible to reliably make mktime return error
-        # on all platfom.  This will make sure that no other exception
+        # It may not be possible to reliably make mktime return an error
+        # on all platforms.  This will make sure that no other exception
         # than OverflowError is raised for an extreme value.
         tt = time.gmtime(self.t)
         tzname = time.strftime('%Z', tt)