python3.pkgs.pyusb: remove unnecessary libusb-compat dependency

It was added in https://github.com/NixOS/nixpkgs/commit/4d7cc55344a18142b4b4120cfe81b18344d78b0b
without any rationale. python2.pkgs.nxt-python seems to build without it.
Maybe it for some reason uses the libusb-0.1 backend but propagating the compat library would not enable that.