kde/kde-frameworks tier4: remove (upstreamed)

KDE Frameworks tier 4 has finally been upstreamed to Alpine Linux! 🎉 Our own package version is currently higher, but from 5.59.0 and onwards the Alpine packages will be used instead.

The resulting packages of the upstreaming process are the same as we have now, so removing our own packages from the binary repo should be possible without any problems. Existing installs will continue using the last pmOS versions, new installs will use the Alpine versions.