Move main window example to manual test

Pick-to: 6.5 6.6
Change-Id: I7d9281f173ce9fb24c0f565797b6fbcfba10459f
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

examples/widgets/doc/src/mainwindow.qdoc

@@ -1,13 +0,0 @@
-// Copyright (C) 2016 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
-
-/*!
-    \example mainwindows/mainwindow
-    \title Main Window
-    \ingroup examples-mainwindow
-
-    \brief The Main Window example shows Qt's extensive support for tool bars,
-    dock windows, menus, and other standard application features.
-
-    \image mainwindow-demo.png
-*/

examples/widgets/mainwindows/CMakeLists.txt

@@ -1,5 +1,4 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
-qt_internal_add_example(mainwindow)
 qt_internal_add_example(menus)

examples/widgets/mainwindows/mainwindows.pro

@@ -1,3 +1,2 @@
 TEMPLATE      = subdirs
-SUBDIRS       = mainwindow \
-                menus
+SUBDIRS       = menus