refactor: fix deprecation up to Qt 6

Signed-off-by: Sefa Eyeoglu <contact@scrumplex.net>

launcher/main.cpp

@@ -24,8 +24,10 @@ int main(int argc, char *argv[])
     return 42;
 #endif
 
+#if QT_VERSION <= QT_VERSION_CHECK(6, 0, 0)
     QApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
     QGuiApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
+#endif
 
     // initialize Qt
     Application app(argc, argv);