Draft: Fix macOS QVTKRenderWindowInteractor hang on Qt 6.10.1
On this platform, every time VTK rendered, a Qt paint event occurred, which in turn caused a render, and the QVTKRenderWindowInteractor got stuck due to the continuous stream of calls to paintEvent() and Render().
Oddly, the render only causes a paint event if the WA_PaintOnScreen is set, and removing this flag fixes the issue.
Closes #19915
Backport: release
Edited by David Gobbi