Forced fixed undo history to make editor shortcuts use global history.

Fixes #76851.

editor/editor_settings_dialog.cpp

@@ -332,7 +332,10 @@ void EditorSettingsDialog::_update_shortcut_events(const String &p_path, const A
 	Ref<Shortcut> current_sc = EditorSettings::get_singleton()->get_shortcut(p_path);
 
 	EditorUndoRedoManager *undo_redo = EditorUndoRedoManager::get_singleton();
-	undo_redo->create_action(vformat(TTR("Edit Shortcut: %s"), p_path));
+	undo_redo->create_action(vformat(TTR("Edit Shortcut: %s"), p_path), UndoRedo::MERGE_DISABLE, EditorSettings::get_singleton());
+	// History must be fixed based on the EditorSettings object because current_sc would
+	// incorrectly make this action use the scene history.
+	undo_redo->force_fixed_history();
 	undo_redo->add_do_method(current_sc.ptr(), "set_events", p_events);
 	undo_redo->add_undo_method(current_sc.ptr(), "set_events", current_sc->get_events());
 	undo_redo->add_do_method(EditorSettings::get_singleton(), "mark_setting_changed", "shortcuts");