When using windeployqt on a Windows Exe/Dll using WebEngine, i get this message : 
D:\Qt\6.9.1\msvc2022_64\resources\qtwebengine_devtools_resources.debug.pak does not exist

And it does not exist,sure. The release version exists : qtwebengine_devtools_resources.pak
But not the .debug file

If i rename the release version with .debug at the end i now get :
D:\Qt\6.9.1\msvc2022_64\resources\qtwebengine_resources.debug.pak does not exist.
So the same problem occurs on this one too

Then D:\Qt\6.9.1\msvc2022_64\resources\qtwebengine_resources_100p.debug.pak does not exist.

Strangely, these .debug files do not exist in Qt 6.8.3 and the windeployqt works there...

Workaround try (failed) : Renaming the qtwebengine_devtools_resources.pak to qtwebengine_devtools_resources.debug.pak and doing the same with subsequent files allows the deployment to go on, but the application crashes on startup, which is expected maybe...