Qt 6.5.4 don't generate XDG_RUNTIME_DIR

due to this change
https://code.qt.io/cgit/qt/qtbase.git/commit/src/gui/kernel/qguiapplication.cpp?h=6.5&id=fa62733c207cef2e4f542b313401578e4affa179
Qt won't create XDG_RUNTIME_DIR if it does not exist.

if without that change, Qt will create the XDG_RUNTIME_DIR folder with the following function stack.

checkNeedPortalSupport
　→　locate(RuntimeLocation)
　　→　writableLocation(RuntimeLocation)
　　　→　checkXdgRuntimeDir　// create XDG_RUNTIME_DIR here via QT_MKDIR

do we intend to change behaviour like this?

If yes, we shall also give instructions to the user on how to build a runtime environment for wayland.