py-scipy and py-pandas with python[39-310]

[Paolo Vincenzo Olivo <vins%NetBSD.org@localhost>]

I see math/py[39-310]-pandas and math/py[39-310]-scipy failing on all
NetBSD bulk builds for pkgsrc-trunk.     
 
Looking at the build log, it seems that meson fails to find
devel/py-cython even if it's pulled as TOOL dependency. Apparently meson
only looks for binaries named `cython' and `cython-3.11' (probably
reflecting PYTHON_VERSION_DEFAULT ?).    
devel/py-cython will install bin/cython-${PYVERSSUFFIX}, so the build
should be adjusted to look for the correct binary depending on the
python version in use.

Anybody using python39/310 packages and willing to fix this?