Require Qt 6.6 & KDE Frameworks 6.0.0, add `.flatpak-builder/` to `.gitignore`
Also removes "-DBUILD_WITH_QT6=ON"
from kirigami-addons
as it should build with Qt6 by default and removes Android QT_MIN_VERSION
:
if (ANDROID)
set(QT_MIN_VERSION "5.15.10")
endif()