tst_qopengl: set surfaceType explicitly

Parent window in sizeLessWindow test was using software pipeline at
least on webOS, causing a QCRITICAL() exit when the test was executed.

Fixes: QTBUG-101869
Pick-to: 6.3
Change-Id: Ie8cc0ea0b6a09729475389be44197e01a45b217f
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

tests/auto/gui/qopengl/tst_qopengl.cpp

@@ -1182,6 +1182,7 @@ void tst_QOpenGL::sizeLessWindow()
     // child window
     {
         QWindow parent;
+        parent.setSurfaceType(QWindow::OpenGLSurface);
         QWindow window(&parent);
         window.setSurfaceType(QWindow::OpenGLSurface);