Orphaned libyui stack in Fedora

[Neal Gompa]

Hey folks,

Now that the ManaTools project no longer uses libyui, and libyui-mga
has been retired upstream, I've orphaned the libyui stack in Fedora,
as nothing uses it anymore.

The following source packages were orphaned:

* libyui
* libyui-gtk
* libyui-mga
* libyui-mga-gtk
* libyui-mga-qt

While SUSE still maintains libyui, it is no longer actively developed
as YaST as a project is also being wound down as they move toward
Agama.