https://github.com/encode/httpx/blob/master/CHANGELOG.md
> The allow_redirects flag is now follow_redirects and defaults to False.

[...]

> The raise_for_status() method will now raise an exception for any responses
> except those with 2xx status codes. Previously only 4xx and 5xx status codes
> would result in an exception.

Co-Authored-By: Jean-Paul Calderone <jean-paul@privatestorage.io>

This also update ZKAPAuthorizer to a python3 using version.

Thanks @jcalderone for pointing me to it

Else the script will fail if the links are already there and not
rotate the preshared.key.

Also now write out a new preshared.key before creating the links
just in case that flag gets lost again.