Use old palette change detection method on Windows 10 and under

Signed-off-by: Claudio Cambra <claudio.cambra@nextcloud.com>

src/libsync/theme.cpp

@@ -969,8 +969,15 @@ void Theme::connectToPaletteSignal()
 {
     if (!_paletteSignalsConnected) {
         if (const auto ptr = qobject_cast<QGuiApplication *>(QGuiApplication::instance())) {
-            connect(ptr, &QGuiApplication::paletteChanged, this, &Theme::systemPaletteChanged);
+#ifdef Q_OS_WIN
-            connect(ptr->styleHints(), &QStyleHints::colorSchemeChanged, this, &Theme::darkModeChanged);
+            // Windows 10 does not have proper dark mode support via Qt 6 so hack detection
+            if (!IsWindows11OrGreater()) {
+                connect(ptr, &QGuiApplication::paletteChanged, this, &Theme::darkModeChanged);
+            } else
+#endif
+            {
+                connect(ptr->styleHints(), &QStyleHints::colorSchemeChanged, this, &Theme::darkModeChanged);
+            }
             _paletteSignalsConnected = true;
         }
     }