prerequisites: missing openSUSE / MicroOS / Kubic

[stuartpb]

https://kubic.opensuse.org/ does ship with open-iscsi preinstalled, but systemctl enable --now iscsid is not enough to enable it.

[stuartpb]

Correction: Kubic used to preinstall open-iscsi: this appears to no longer be the case.

Users of Kubic will need to run transactional-install pkg install open-iscsi first, or, if they want the service to start before activated by socket, run transactional-install shell and then

zypper install open-iscsi
systemctl enable iscsi.d