[3.14] gh-133886: Fix sys.remote_exec() for non-UTF-8 paths (GH-133887) (GH-133963)

It now supports non-ASCII paths in non-UTF-8 locales and
non-UTF-8 paths in UTF-8 locales.
(cherry picked from commit c09cec5d69f2ef6ab5e64c7e0579fbd9dcb2ca45)

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