Boot delay due to systemd-networkd-wait-online.service

[Ian Collier]

Using Ubuntu 24.04 Server autoinstall, if the 'ubuntu-settings' package happens to get installed on the system as a result of specifying extra packages to install, then there will be an unnecessary 2-minute delay on the post-install boot-up, because:

 - the netplan config installed by subiquity does not contain a renderer
 - ubuntu-settings sets the default renderer to NetworkManager
 - systemd-networkd-wait-online.service is activated during the boot, and it does not care whether or not NetworkManger has established a network connection.

In some instances, systemd-networkd-wait-online.service starts twice, once before
cloud-init (when NetworkManager has not started) and once after - thus 4 minutes of
delay.