do.py: added explicit call to cython
do.py: added explicit call to cython

for the time being to see whether this fixes the CI failure
oaelhara/numbbo,dtusar/coco,NDManh/numbbo,NDManh/numbbo,oaelhara/numbbo,dtusar/coco,dtusar/coco,oaelhara/numbbo,NDManh/numbbo,oaelhara/numbbo,dtusar/coco,NDManh/numbbo,dtusar/coco,NDManh/numbbo,dtusar/coco,oaelhara/numbbo,oaelhara/numbbo,NDManh/numbbo,oaelhara/numbbo,dtusar/coco,NDManh/numbbo,dtusar/coco,NDManh/numbbo,NDManh/numbbo,dtusar/coco,oaelhara/numbbo,oaelhara/numbbo