Disable KDBusService on Haiku
While Haiku doens't have KF6 for now (still atleast missing qt6webengine for some parts), this fixes not having to export dbus-launch before launching the app (or patching main.cpp to do a autolaunch/kill the deamon). For the record, I'm running KF6 6.1.0 here together with Qt6.7 and managed to build/run 24.02.2 on Haiku.