Port to KF6
Kdenlive currently has a linux-qt6 CI build, but isn't properly ported to KF6, i.e. it still uses KF5:: targets.
This works because there is a special "hybrid" CI configuration that builds kf5 against Qt6. This was only ever meant as a transitional helper while projects are adapted to KF6.
Since most projects are ported now we would like to discontinue those hybrid builds since they are somewhat costly to maintain. Kdenlive is one of the few remaining projects relying on those builds.
Can you please look into properly supporting KF6 builds?
Build-system wise this is mostly s/KF5/KF${QT_MAJOR_VERSION}/, but there may be other issues due to the difference between those hybrid builds and proper KF6. This difference will only grow larger over time, so it's better to do it sooner than later