Fails to build against Qt6 on Windows

[MehdiChinoune]

Describe the bug When trying to build leocad 23.03 against Qt6 it fails to build because of a missing header that no longer exists with Qt6

clang++ -c -include release/lc_global.h -O2 -g -Wall -Wextra -Wextra -Wno-ignored-attributes -Wno-unused-parameter -fexceptions -DUNICODE -D_UNICODE -DWIN32 -DMINGW_HAS_SECURE_API=1 -DLC_DISABLE_UPDATE_CHECK=1 -DQT_NO_DEBUG -DQT_PRINTSUPPORT_LIB -DQT_OPENGLWIDGETS_LIB -DQT_WIDGETS_LIB -DQT_OPENGL_LIB -DQT_GUI_LIB -DQT_NETWORK_LIB -DQT_XML_LIB -DQT_CONCURRENT_LIB -DQT_CORE_LIB -DQT_NEEDS_QMAIN -I../leocad-23.03 -I. -I../leocad-23.03/qt -I../leocad-23.03/common -ID:/M/msys64/clang64/include/qt6 -ID:/M/msys64/clang64/include/qt6/QtPrintSupport -ID:/M/msys64/clang64/include/qt6/QtOpenGLWidgets -ID:/M/msys64/clang64/include/qt6/QtWidgets -ID:/M/msys64/clang64/include/qt6/QtOpenGL -ID:/M/msys64/clang64/include/qt6/QtGui -ID:/M/msys64/clang64/include/qt6/QtNetwork -ID:/M/msys64/clang64/include/qt6/QtXml -ID:/M/msys64/clang64/include/qt6/QtConcurrent -ID:/M/msys64/clang64/include/qt6/QtCore -Ibuild/release/.moc -Ibuild/release/.ui -I/include -ID:/M/msys64/clang64/share/qt6/mkspecs/win32-clang-g++  -o build/release/.obj/lc_bricklink.o ../leocad-23.03/common/lc_bricklink.cpp
  ../leocad-23.03/common/lc_application.cpp:16:10: fatal error: 'QtPlatformHeaders\QWindowsWindowFunctions' file not found
     16 | #include <QtPlatformHeaders\QWindowsWindowFunctions>

To Reproduce Steps to reproduce the behavior:

1. Setup Qt6 on Windows
2. Build leocad

Expected behavior To build

Version (please complete the following information):

• OS: Windows 10
• LeoCAD Version 23.03

[MehdiChinoune]

Are you going to fix it in the coming days, or just reopened it for later consideration.