After some discussion on matrix when doing some QA on kf6 rpms, I noticed all Qt Designer plugins are going to the libs rpms and not the -devel rpms.

To clarify that, I cross-checked with how Debian does it, and they move the designer plugins to the -dev packages like example here:

https://packages.debian.org/sid/amd64/libkf5itemviews-dev/filelist

I'll first track down which kf6 rpms are affected by this and make according PRs to move the designer plugins to the -devel rpms file lists.

@marcdeop @ngompa @farchord @aleasto