QFontComboBox: inform accessibility about model reset when filter changes

Signals are blocked explicitly, so the modelReset signal that would
normally make the view update the accessibility framework does not work.
Update accessibility explicitly.

Fixes: QTBUG-114423
Change-Id: Iba6f0b9dfb258e85111326184d7899bf0570a5c1
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
(cherry picked from commit a0b7eee6c6af8d233e3bb7bd5c39f9059ec994f0)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/widgets/widgets/qfontcombobox.cpp

@@ -3,6 +3,7 @@
 
 #include "qfontcombobox.h"
 
+#include <qaccessible.h>
 #include <qstringlistmodel.h>
 #include <qitemdelegate.h>
 #include <qlistview.h>
@@ -328,6 +329,13 @@ void QFontComboBoxPrivate::_q_updateModel()
     {
         const QSignalBlocker blocker(m);
         m->setStringList(list);
+        // Since the modelReset signal is blocked the view will not emit an accessibility event
+    #if QT_CONFIG(accessibility)
+        if (QAccessible::isActive()) {
+            QAccessibleTableModelChangeEvent accessibleEvent(q->view(), QAccessibleTableModelChangeEvent::ModelReset);
+            QAccessible::updateAccessibility(&accessibleEvent);
+        }
+    #endif
     }
 
     if (list.isEmpty()) {