x11-themes/plasma5-breeze: add upstream fix for a bug in the cursor icon

The cursor icon could get stuck on the "resize" icon when moving over
side panels in for example x11-fm/dolphin.
See [1] for the details of the bug.

[1] https://bugs.kde.org/show_bug.cgi?id=436473

Obtained from: https://invent.kde.org/plasma/breeze/commit/40d558e96d607419b9bfaa9a706621a906bab3e9