[3.11] gh-113188: Fix shutil.copymode() and shutil.copystat() on Windows (GH-113285...

[3.11] gh-113188: Fix shutil.copymode() and shutil.copystat() on Windows (GH-113285) (GH-113426)

Previously they worked differenly if dst is a symbolic link:
they modified the permission bits of dst itself rather than the file
it points to if follow_symlinks is true or src is not a symbolic link,
and did nothing if follow_symlinks is false and src is a symbolic link.
(cherry picked from commit c7874bb56f862dd96a9a74b809dbea5688fa6c1c)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>