KDE: Update KDE Frameworks 6 to 6.0.0

This updates KDE Frameworks 6 to the first stable release.

Update plan for the rest of KDE:

• The KDE Plasma 6 ports that are currently in the tree will be updated shortly to the stable release.

• The KDE Applications will be updated to 24.02 at the beginning of the next quarter in the tree. They will be mostly Qt6 based. To test them beforehand, one can use the overlay [1].

• The idea is to wait out the first patch-release for the applications, which should hopefully get rid of most of the new bugs.

• The Qt5 bases KDE Frameworks 5 and Plasma 5 ports should remain in the tree for the next quarter -- Frameworks as long as it is required by other ports. The Plasma 5 ports will likely be removed at some point in the future however -- as there is no apparent benefit in having multiple Plasma versions at the moment.

• The Qt6 based KDE applications will replace the current Qt5 based ports. As the maintenance overhead for duplicate is not manageable.

• For co-instability the KDE Frameworks 5 ports will be adapted to depend on the KDE Frameworks 6 ports as described in [2].

• This plan is not fixed in stone, but will be adapted when it seems reasonable to do so.

Announcement: https://kde.org/announcements/megarelease/6/

[1] https://github.com/tcberner/kde6-overlay
[2] https://community.kde.org/Frameworks/6.0_Release_notes#Coinstallability