Alpine's QT5 is built with desktop OpenGL, but we need OpenGL ES2

Created by: ollieparanoid

Reported by @NotKit in #postmarketOS. The quickest solution (to get a proof of concept plasma shell working on a real device) would be if we fork the package and adjust it (with pkgrel=9999), then we could look into upstreaming that change if Alpine agrees on it. We did the same approach for busybox and sdl2, and that worked out well.