This enables documentation building in add-ons and other modules that
need to build docs.
Task-number: QTQAINFRA-3972
Change-Id: Ic2763d6d36d26e5a1267b312727c3c268ad6d114
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
(cherry picked from commit e84e85dd4c59f2c79f81ba4d8d7f04397eb0003c)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
