Remove mandatory dependency on kf5-umbrella for KF5
kdesrc-build currently treats all of KF5 as a mandatory dependency for remaining Qt5-based KDE application, including Plasma 5, the KDE Applications, etc. It does this by adding a virtual dependency on a fake module "kf5umbrella", which itself depends at least on every module in frameworks/*.
This means that any application which depends on KF5 (in the
--include-dependencies sense) will depend on all KF5 modules, not just on direct or indirect dependencies.
This is problematic for compat modules like Kdelibs4Support and KDEWebKit, which may needlessly require added support from the system or even Qt5. KDEWebKit in particular mandates Qt5WebkitWidgets, which is not installed with modern Qt5 installers anymore.
kdesrc-build should remove the mandatory requirement on all of KF5. This would require some cleanup to add proper dependencies for modules which have been implicitly reliant on this feature.
If this is implemented solely using kde-build-metadata dependencies then the fix is simple (just remove the fake dependencies), but I need to check if this is actually implemented directly in kdesrc-build itself to ensure all such dependencies are isolated.