That ‘dependency cycle’ really was simply one package being installed before the other though it expects the other way around. Both get installed. It is only a notice.
As per the thread issue - You just managed to hit a partial upgrade scenario.
As shown by myself and other commenters above .. an extra 30 minutes was apparently the difference here. You upgraded parts of QT but not the parts of Plasma (etc) that rely on it.
Try again with all of them and I am 99.99% it will be fine.