Qt5->Qt6 transition chaos for packagers when depending applications are not yet ported.

Hello everyone!
Obviously we expect there to be bumps in the road while packaging
unstable ( master ), however in most cases you can set
QT_VERSION_MAJOR and dual build qt5 and qt6 version to satisfy both
qt5 and qt6 applications. I have stumbled on libkgapi which master
does not support this and will only build qt6. kio-gdrive is not yet
ported and as such creating a bit of chaos with apt. We have come up
with a workaround, but shouldn't libraries still support both when
there are applications out there that still depend on the qt5 variant?
Thanks,
Scarlett