[Bug]: Cascade layout not available

[ikajdan]

Summary

The cascade layout exists in the source code, but it's not present in the Window Layout list.

Steps to Reproduce

1. Go to System Settings > Window Tiling > Window Layouts.
2. Cascade layout is not listed.

Expected behavior

Cascade layout should be available to the user.

Screenshots

No response

Bismuth version

master

KDE Plasma version

5.22.5

The platform KWin is running on

X11

Additional context

No response