assert qt and kf5 versions against their actual underlying value
Summary:
this isn't super useful to compare other than the calls don't explode,
doesn't have a downside either though...
Test Plan: test still passes
Reviewers: tcanabrava
Reviewed By: tcanabrava
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D22232