Accent color change crashes KeePassXC with macOS Sonoma

[varjolintu]

Overview

Changing Accent color in macOS crashes KeePassXC.

Steps to Reproduce

1. Start KeePassXC
2. Go to macOS System Preferences and change Accent color
3. KeePassXC crashes

Context

Can be reproduced during debugging. Console has the following error:

KeePassXC[5831:127741] [General] An uncaught exception was raised
KeePassXC[5831:127741] [General] -[AppKitImpl interfaceThemeChanged:]: unrecognized selector sent to instance 0x10a583560

KeePassXC - From 2.7.6 to 2.8.0-snapshot
Build Type: Snapshot
Revision: dff2f18

Operating System: macOS Sonoma 14.3.1

[varjolintu]

Everything works just fine after removing this: https://github.com/keepassxreboot/keepassxc/blob/develop/src/gui/osutils/macutils/AppKitImpl.mm#L45
Is it really needed? The event is still catched inside observeValueForKeyPath().

[varjolintu]

A similar fix was made earlier: #8615