python3: 3.10 -> 3.11

[mweinelt]

Updates the default python version to 3.11, while keeping 3.10 around until after the NixOS 23.11 release.

Description of changes

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 23.11 Release Notes (or backporting 23.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

[AndersonTorres]

Because, why not?

[NickCao]

Shall we also update doc/languages-frameworks/python.section.md and the release note?

[raboof]

Shall we also update doc/languages-frameworks/python.section.md and the release note?

I've created a commit proposing those updates in 4b0b9d0 . I expect there will be some review comments / iteration on getting this 'just right'.

I would propose we merge this PR as-is so we can start ironing out any bugs with python 3.11 ASAP, and iterate on the messaging in parallel.

[mweinelt]

This should go through python-updates, so we can inspect and iterate on the fallout before it hits staging.

cc @tjni do you want to drive this?

[tjni]

Sure thing!

[tjni]

I have been working on addressing some fallout from #248866, but I'll start working on this tomorrow.

[mweinelt]

Continues on python-updates.