Summary:
Remove anchors within `Kirigami.AbstractListItem` delegates.
They were causing random misalignment of items in the main and the overlay `ListView`s
Test Plan:
Before {F8284332}
After {F8284333}
Reviewers: broulik, #vdg, #kwin, ngraham
Reviewed By: #vdg, ngraham
Subscribers: ahiemstra, ngraham, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D29423