This is the qt5 counterpart to the qtbase instructions to allow
using configure instead of cmake when configuring a top-level build.
Pick-to: 6.2 6.3
Task-number: QTQAINFRA-4357
Task-number: QTQAINFRA-4815
Change-Id: Ie5af31f9349a6dd88fa7699d40dad659180814e2
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Toni Saario <toni.saario@qt.io>