QtWebengine needs to be skipped with Windows 11 on ARM

Currently Windows 11 on ARM fails with qtwebengine build:

https://testresults.qt.io/coin/integration/qt/qt5/tasks/nightly1713743221

qtwebengine build:

https://testresults.qt.io/coin/log/qt/qtwebengine/d9b97fc1b67db1f5cbc5fbb3b38d01da5b058701/WindowsWindows_11_22H2aarch64WindowsWindows_11_22H2aarch64MSVC2022qtci-windows-11_22H2-aarch64-51-5f4198DebugAndRelease_InsignificantTests_Sccache_UseConfigure/0cbce1326890a5830d45da57e9457cc3ea852193/build_1713743247

agent:2024/04/22 01:22:57 build.go:404: CMake Error at cmake/Functions.cmake:639 (message): 
agent:2024/04/22 01:22:57 build.go:404: Unknown architecture: ARM64

WoA should already be excluded in qtwebengine, but previously PROCESSOR_ARCHITECTURE (which is the source for CMAKE_SYSTEM_PROCESSOR used to exclude arm64), is compared with 'arm64' not with 'ARM64'

http://bugreports.qt.io/browse/QTBUG-94065

https://codereview.qt-project.org/c/qt/qtwebengine/+/351551

Fix for this ticket has been created and tested:

https://codereview.qt-project.org/c/qt/qtwebengine/+/556537

There is other discussion when Chromium is supporting Windows on ARM, but there's currently not enough information of that - therefore qtwebengine is excluded from Windows on ARM for now.