Python 3.10 support

[C0rn3j]

At minimum this is blocked by:

• lxml==4.6.2, 4.6.5 or later would work.
• psycopg2==2.8.6, would need a version bump to the latest 2.9.3
• typed-ast==1.4.1, supposedly supports it but I got a build error, bumping to 1.5.2 works

[BassOfBass]

Yeah but what are the killer features of 3.10?

[C0rn3j]

Not having to install an extra Python version would be handy.

My distribution ships with 3.10 already.

[BassOfBass]

Juggling different python versions is the lifeblood of python development though. But no, it's not going to happen out of convenience, partly because my scuffed setup can't run python higher than 3.8. The lead dev isn't a big fan of dependency management either, especially if there are no bugs with the current versions.