archivers/py-zipstream-ng: Update to 1.6.0

ChangeLog:
https://github.com/pR0Ps/zipstream-ng/blob/master/CHANGELOG.md#v160

• Add the ability to provide a custom "walk" function to ZipStream.add_path for more control over how directories are walked.
• Change the exception raised when trying to add a file that doesn't exist from a ValueError to a more appropriate FileNotFoundError.
• Optimize the number of os.stat calls required to add a file.
• Fix issue where adding data with an arcname that contained a null byte would lead to an incorrect size being calculated.
• When ZipStream.add is provided a size alongside an iterable, the size will now be used to determine if Zip64 extensions are needed.

PR: 271746