Build with statically linked Qt 6 cannot find qrc_qmake*.cpp.o files

When building our iOS app with the static Qt 6 build I got the following error:

clang: error: no such file or directory: '$$[QT_INSTALL_PREFIX]/./qml/QtQml/objects-Release/Qml_resources_1/.rcc/qrc_qmake_QtQml.cpp.o'

And a bunch more for different modules.

Some investigating showed that this is caused by the install prefix not being properly replaced in the plugins.list file generated by the qml.qbs module.

However, simply fixing this tag replacement caused a different kind of error: I got lot's of "duplicate symbols" because those object files are listed both in the plugins.list and in the staticLibs property since they're both taken straight from the .prl file. I don't know which version would be correct here.