[Reg 6.2.13->6.5] "CONFIG += qtquickcompiler" no longer works when cross-compiling

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

Notes

• I added message("Hello") to the top of C:\Qt\6.8.1\Boot2Qt\raspberrypi-armv8\toolchain\sysroots\x86_64-w64-mingw32\usr\lib\mkspecs\features\qtquickcompiler.prf – however, the message is not printed when I run qmake on the attached project. So it looks like qtquickcompiler.prf isn't getting loaded at all.
• The "Hello" test works as expected on a Desktop kit.