Moving KGraphViewer & Massif Visualizer to KDE Gear

[Friedrich W. H. Kossebau]

Hi,

I would like to propose moving both KGraphViewer (invent.kde.org/graphics/
kgraphviewer) & Massif Visualizer (invent.kde.org/sdk/massif-visualizer) to 
the KDE Gear release bundle on next occasion.

Both are rather stable in their feature-set and "community-maintained".
As such community maintenance, they just got finally their Qt6 port completed 
and turned Qt6-only in the master branches.

Ideally the "next occasion" would already be KDE 24.05, if that would be still 
acceptable given the history of the repos.

While adding more work onto the Gear release managers already now, it would 
save individuals (like myself) from trying to do custom releases work, where 
otherwise the Gear release automation could free some time to e.g. do any 
needed regression finding & fixing.

Cheers
Friedrich