The array methods fromstring/tostring have been deprecated since Python
3.2. Python 3.9 removes them completely.

This was discovered when trying to build gitdb package for Fedora 33.
https://bugzilla.redhat.com/show_bug.cgi?id=1788660

Our user was experiencing issue [1] when using a git repository on NTFS mount
running on Linux. The current check checks if we are running on Windows, but
it should really check if we are on NTFS. And since checking fs type is not
that trivial and not efficient, it is simpler and better to just always apply
NTFS-specific logic, since it works on other filesystems as well.

[1] https://github.com/iterative/dvc/issues/1880#issuecomment-483253764