Qt Creator enforces Python syntax highlight onto Cython code

Qt Creator editor assumes *.pyx files must be highlighted as Python *.py files.

By providing corresponding .xml file, Qt Creator highlight correctly YAML files, for instance. But even if we provide a specific (and much better) Cython highlight .xml file, it gets ignored it and keeps using the Python highlighter. Both .xml files work perfectly in the KDE Kate editor.

I already tried to break up any Python association to .pyx files in the Environment -> MIME types to no avail.