Patch for breeze to fix splitter proxy (bug 436473)

[Fabian Vogt]

Hi,

https://bugs.kde.org/show_bug.cgi?id=436473 is a regression in Plasma/5.18,
5.21.5 and 5.21.90, or if the commit "Fix SplitterProxy not clearing when
above another QSplitterHandle" was backported. It is fixed by f99b7ef6
("Fix informing the underlying widget when leaving SplitterProxy") 
in master and cherry-picked to Plasma/5.22 and Plasma/5.18 branches.

The next version of Plasma with the fix included will be 5.22.0, which is
planned to be released in 11 days, so you might want to apply the fix to your
5.21.5 packages:

https://invent.kde.org/plasma/breeze/-/commit/f99b7ef621c9c69544158d245699fd8104db6753.patch

Cheers,
Fabian