This class is useful for migrating config from kde4
not sure that it will be useful in kf6.
We use it in Kdelibs4ConfigMigrator so it will be useful to move it in kf5support for helping to port it.
Perhaps a dummy class in kf5support as it will not very useful

Conclusion from the 2021-04-21 frameworks meeting: Do not deprecate in 5, so this remains working and isn't dropped as part of preperational porting, and remove for 6.

We should still inform consumers about this being removed in KF6, for this a Qt major version visibility guard & docstring message should suffice. Deprecation warnings would annoy consumers of API who want to keep compatibility with really old config file locations. In the worst case they will simply have to remove those few lines when they port to KF6 :)

https://invent.kde.org/frameworks/kcoreaddons/-/merge_requests/172