Install the part in kf5/parts/

https://lxr.kde.org/search?%21v=kf5-qt5&_filestring=&_string=%22arkpart%22
says nothing is hardcoding the path to the part, so it should be fine.

Tested in konqueror, RMB on zip file, preview in -> Archiver

KF6 task: https://phabricator.kde.org/T12340