mkosi-initrd enablement on openSUSE (osc25)

`mkosi-initrd` is a tool for building initrds using distribution packages that is gaining interest among systemd distributions, and can currently be used on openSUSE Tumbleweed. We will analyze in detail how it works, its weaknesses and its benefits, in order to ultimately try to provoke a change of mindset in developers accustomed to thinking only about `dracut` when implementing functionalities that have to run in the initrd. More information: [https://en.opensuse.org/Mkosi-initrd](https://en.opensuse.org/Mkosi-initrd) Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://c3voc.de