Upgrade to python 3.11

[sash-a]

Please describe what needs to be maintained?

Upgrade python version, we are on 3.9, which is almost 3 years old at this point.

Big reason for this is the discussion in #940 about having generic named tuples, which isn't possible in 3.9 or 3.10. But 3.11 brings other benefits also.

I have tested this locally and it worked out of the box.