Add Py3.10 as CI test target.
Add Py3.10 as CI test target.

da-woods/cython,cython/cython,cython/cython,scoder/cython,da-woods/cython,cython/cython,scoder/cython,scoder/cython,da-woods/cython,da-woods/cython,cython/cython,scoder/cython