Test Plan:
Ran

```lang=sh
xprop -root -f _KDE_KWIN_KSCREEN_SUPPORT 32c -set _KDE_KWIN_KSCREEN_SUPPORT 1

sleep 5

xprop -root -f _KDE_KWIN_KSCREEN_SUPPORT 32c -set _KDE_KWIN_KSCREEN_SUPPORT 3
```

Reviewers: #kwin, davidedmundson

Reviewed By: #kwin, davidedmundson

Subscribers: kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D13865