Orphaned adapta-gtk-theme, adapta-backgrounds

Hello packagers,

I've just orphaned both adapta-gtk-theme and adapta-backgrounds.

The upstream project is more or less dead, since the main developer
left after getting a lot of negative feedback for the release of a big
refresh / redesign of the Adapta GTK theme (which was then reverted).
The fedora package currently provides the last version of the theme
*before* the redesign.

I originally took over these packages because I used them myself, but
since fedora 30 I'm using stock GNOME / Adwaita again, and so I don't
have any use for them anymore.

Additionally, since the last inkscape update (move to gtk3 and
python3?), the theme assets rendering during the build process is now
broken, and this would need to be fixed as well.