Fix doxygen producing different results on 32 and 64 bit architectures
    
    This is a fix for a regression introduced in version 1.8.17 that causes
    doxygen to create different results on 32 and 64 bit achitectures.
    This is a problem in Fedora because koji rejects builds where noarch
    subpackages built on different architectures contain different sets
    of files. See:
    https://bugzilla.redhat.com/show_bug.cgi?id=1814356
    https://github.com/doxygen/doxygen/issues/8022