Unable to build VTK 9.4 with Qt 6.8

[sankhesh (Sankhesh Jhaveri)]

@Daan_Baas

compile VTK by adding ‘-DQt6QmlTools_DIR:PATH=${QT_EXT_BUILD}/lib/cmake/Qt6QmlTools’ to VTK’s ExternalProject_Add CMAKE_ARGS.

That seems fine for now. I looked into it a little and it seems like a Qt6 cmake config issue.