Plasma repos that will be dropped with 6.8

[Nicolas Fella]

Hi,

beginning with Plasma 6.8 we will drop a number of X11-specific 
repositories from the Plasma release. These are:

- kwin-x11

- kgamma

- wacomtablet

I'm telling you well in advance so you can plan translation stuff 
accordingly.

Cheers

Nico