/usr/include/Inventor/Qt/ is in libsoqt-dev-common 1.6.0~e8310f-4.
This file is owned by root:root, with mode 0o755.
..
/usr/include/Inventor/Qt/SoQt.h
/usr/include/Inventor/Qt/SoQtBasic.h
/usr/include/Inventor/Qt/SoQtColorEditor.h
/usr/include/Inventor/Qt/SoQtComponent.h
/usr/include/Inventor/Qt/SoQtCursor.h
/usr/include/Inventor/Qt/SoQtGLWidget.h
/usr/include/Inventor/Qt/SoQtObject.h
/usr/include/Inventor/Qt/SoQtRenderArea.h
/usr/include/Inventor/Qt/devices/
/usr/include/Inventor/Qt/devices/SoQtDevice.h
/usr/include/Inventor/Qt/devices/SoQtKeyboard.h
/usr/include/Inventor/Qt/devices/SoQtMouse.h
/usr/include/Inventor/Qt/editors/
/usr/include/Inventor/Qt/editors/SoQtColorEditor.h
/usr/include/Inventor/Qt/editors/SoQtMaterialEditor.h
/usr/include/Inventor/Qt/engines/
/usr/include/Inventor/Qt/nodes/
/usr/include/Inventor/Qt/nodes/SoGuiColorEditor.h
/usr/include/Inventor/Qt/nodes/SoGuiMaterialEditor.h
/usr/include/Inventor/Qt/viewers/
/usr/include/Inventor/Qt/viewers/SoQtConstrainedViewer.h
/usr/include/Inventor/Qt/viewers/SoQtExaminerViewer.h
/usr/include/Inventor/Qt/viewers/SoQtFlyViewer.h
/usr/include/Inventor/Qt/viewers/SoQtFullViewer.h
/usr/include/Inventor/Qt/viewers/SoQtPlaneViewer.h
/usr/include/Inventor/Qt/viewers/SoQtViewer.h
/usr/include/Inventor/Qt/widgets/
/usr/include/Inventor/Qt/widgets/SoQtPopupMenu.h
/usr/include/Inventor/Qt/widgets/SoQtThumbWheel.h