Since the PTI switched the supported python versions for the current
cycle from 3.8+3.9 to 3.9+3.10, we want to update the constraints
generation accordingly. Since we don't have a stable platform where we
can run both py3.9 and py3.10 in parallel, generate constraints only for
py3.10 for now.
Change-Id: I4a4d9cb6e292bb693ae424be0928501fed81113f