They cause make to run much slower, and qmake writes everything
explicitly, so they're not really needed.
Change-Id: Ia47674eec8309e120c8264b7b6687677a520d5b9
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>