drop tooltip flag from reproducer windows (needs transient parent on wayland)

test/screen-uaf-reproducer/main.cpp

@@ -41,7 +41,6 @@ int main(int argc, char *argv[])
         auto w = std::make_unique<QWindow>();
         w->setTitle(QStringLiteral("uaf-%1").arg(i));
         w->resize(1, 1);
-        w->setFlag(Qt::ToolTip); // small, no decoration, no focus
         w->show();
         windows.push_back(std::move(w));
     }