x11-toolkits/como: unbreak build with clang 19

In file included from examples/minico/main.cpp:7:
In file included from como/base/wayland/platform.h:15:
como/render/wayland/platform.h:255:19: error: no member named 'addRepaintFull' in 'platform<Base>'; did you mean 'addRepaint'?

255 |             this->addRepaintFull();
    |                   ^~~~~~~~~~~~~~
    |                   addRepaint

como/render/wayland/platform.h:220:10: note: 'addRepaint' declared here

220 |     void addRepaint(QRegion const& region)
    |          ^

Reported by: pkg-fallout