QWindows11Style: Reduce menubar height in QTabWidget

Due to increased menubar height, an attached menubar to QTabWidgets was
shown as >> indicator. This patch reduces the size of the menubar, in
case it is attached to a QTabWidget.

Fixes: QTBUG-130399
Pick-to: 6.8
Change-Id: I0e71156cacd6acc51ede353b3b4ddf09d9c0260f
Reviewed-by: Christian Ehrlicher <ch.ehrlicher@gmx.de>

src/plugins/styles/modernwindows/qwindows11style.cpp

@@ -24,6 +24,9 @@
 #if QT_CONFIG(datetimeedit)
 #  include <QtWidgets/qdatetimeedit.h>
 #endif
+#if QT_CONFIG(tabwidget)
+#  include <QtWidgets/qtabwidget.h>
+#endif
 #include "qdrawutil.h"
 #include <chrono>
 
@@ -2030,6 +2033,9 @@ QSize QWindows11Style::sizeFromContents(ContentsType type, const QStyleOption *o
             constexpr int hPadding = 2 * 11;
             constexpr int itemHeight = 32;
             contentSize.setWidth(contentSize.width() + hMargin + hPadding);
+#if QT_CONFIG(tabwidget)
+            if (widget->parent() && !qobject_cast<const QTabWidget *>(widget->parent()))
+#endif
                 contentSize.setHeight(itemHeight);
         }
         break;