graphics/kolourpaint: Move palattes to app-specific dir

In kolourpaint 25.8.0, the color palatte files originally shipped with
devel/kf5-kdelibs4support were added to the source to fix [1], but were
erroneously installed into a global location [2].

While [1] has been crudely resoloved, [2] has not yet been addressed.
The kde@ team has determined [2] to be the most sensible way to move
forward to mitigate conflicts between graphics/kolorpaint and
devel/kf5-kdelibs4support.

While here:
Pet portclippy(1)
Remove unneeded deps

[1] https://bugs.kde.org/show_bug.cgi?id=501341
[2] https://bugs.kde.org/show_bug.cgi?id=507007