The project wizards generate a qt.cmake that contains a qt_standard_project_setup implementation for older Qt versions

if(QT_VERSION VERSION_LESS 6.3)
    macro(qt_standard_project_setup)
        set(CMAKE_AUTOMOC ON)
        set(CMAKE_AUTORCC ON)
        set(CMAKE_AUTOUIC ON)
    endmacro()
endif()

This function should not set CMAKE_AUTORCC. We discourage its usage in favor of qt_add_resources.