Work around high DPI issues on Windows

Task-number: QTBUG-80934
Change-Id: I4b7dbe7157145db3a9feee83f32be3babaca5ab9
Reviewed-by: David Schulz <david.schulz@qt.io>

src/app/main.cpp

@@ -335,6 +335,11 @@ static void setHighDpiEnvironmentVariable()
             && !qEnvironmentVariableIsSet("QT_SCALE_FACTOR")
             && !qEnvironmentVariableIsSet("QT_SCREEN_SCALE_FACTORS")) {
         QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
+#if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)
+        // work around QTBUG-80934
+        QGuiApplication::setHighDpiScaleFactorRoundingPolicy(
+            Qt::HighDpiScaleFactorRoundingPolicy::Round);
+#endif
     }
 }