Publish builds for Python 3.10

[svet-b]

At the moment installation on the most recent Python version is not possible, since published builds on PyPi only exist up to 3.9. As you mention in the README, the builds should in principle be compatible (or be made compatible by changing the Python version to none). But for the time being - for anyone who isn't looking to fork this, build it themselves, and set up a custom install mechanism - simply running pip install pyjsonata unfortunately fails with No matching distribution found.