util_ships.py:ship_file_name() could use `pathlib.PureWindowsPath.is_reserved()`

[Athanasius]

Rather than trying to maintain a list of 'reserved' file names ourselves.

[A-UNDERSCORE-D]

note that is_reserved is available on Path itself as well, which would be even cleaner than going directly to PureWindowsPath and would mean no need to a platform guard

[A-UNDERSCORE-D]

close != comment. Whoops.