Build without X11 for qt6

[oniGino]

Looks like you have some effort towards Native Wayland environments but still call some X11 libraries unconditionally.

In cases where qt6base is build without X11 support numerous compiletime errors regarding

blur/blurhelper.cpp:52:74: error: no member named 'QX11Application'
style/themeconfig/ThemeConfig.cpp:595:74: error: no member named 'QX11Application' in namespace 'QNativeInterface'

as a some examples..

At a glance I think if defined could be adjusted to a nested structure where

#if (QT_VERSION < QT_VERSION_CHECK(6,0,0))
...
-#else
+#elif defined Q_WS_X11
...

or something like that
or maybe don't use Q_WS_X11 at all?

Thanks for all your work

[tsujan]

In cases where qt6base is build without X11 support

Why should someone build qt6base without X11 support?!

[MarkusTieger]

Less dependencies, which you don't need