`qvm-template purge` fails when dependents have networking inter-dependencies

[deeplow]

Qubes OS release

Qubes 4.2

Brief summary

When removing Whonix 17 (e.g. a completely clean Whonix 18 install) running qvm-template purge fails mid-way.

Steps to reproduce

Run qvm-purge whonix-gateway-17 whonix-workstation-17 and accept the confirmation dialogues.

Expected behavior

Successful removal of all Whonix-related VMs

Actual behavior

[user@dom0] $ qvm-purge whonix-gateway-17 whonix-workstation-17
[...]
This will completely remove the selected VM(s) (confirmation 3 of 3)...
  whonix-workstation-17-dvm
  sys-whonix
  anon-whonix
Are you sure? [y/N] y
Property 'default_dispvm' of 'anon-whonix' set to 'dummy'.
ERROR: The dummy qube does not provide network

Additional information

I believe the issue is that because the temporary dummy does not have provides_network, it cannot be set as the temporary netvm of the derived qubes. I believe the problem is around this part of the code.