[Reg 6.2.13->6.5] qtquickcompiler.prf is missing from cross-compiling kits, so "CONFIG += qtquickcompiler" no longer works when cross-compiling

Problem

Try building the attached project. Desktop (non-cross-compiling) kits still run qmlcachegen as expected, but cross-compiling kits no longer run qmlcachegen.

• Tested on Qt 5.15.18 (Works): Android, iOS, Boot2Qt
• Tested on Qt 6.2.13 (Works): iOS
• Tested on Qt 6.5/6.8 (Doesn't work): Android, iOS, Boot2Qt, WebAssembly

Workaround

Manually copy qtquickcompiler.prf from a desktop/host kit to the cross-compiling kit. For example:

• From C:\Qt\6.8.1\Boot2Qt\raspberrypi-armv8\toolchain\sysroots\x86_64-w64-mingw32\usr\lib\mkspecs\features
• To C:\Qt\6.8.1\Boot2Qt\raspberrypi-armv8\toolchain\sysroots\cortexa53-poky-linux\usr\lib\mkspecs\features