[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/sysconfig.py b/Lib/sysconfig.py
index 95b48f6..daf9f00 100644
--- a/Lib/sysconfig.py
+++ b/Lib/sysconfig.py
@@ -184,7 +184,7 @@ def is_python_build(check_home=False):
 
 if _PYTHON_BUILD:
     for scheme in ('posix_prefix', 'posix_home'):
-        # On POSIX-y platofrms, Python will:
+        # On POSIX-y platforms, Python will:
         # - Build from .h files in 'headers' (which is only added to the
         #   scheme when building CPython)
         # - Install .h files to 'include'