Add support for PEP 798 and 810

[JelleZijlstra]

Fixes #5042

[github-actions]

diff-shades results comparing this PR (b71f022) to main (69cfa4c):

--preview style: no changes

--stable style: no changes

---

What is this? | Workflow run | diff-shades documentation

[hugovk]

GitHub failed to download the checkout action! 🙃

Download action repository 'actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd' (SHA:de0fac2e4500dabe0009e67214ff5f5447ce83dd)
Warning: Failed to download action 'https://api.github.com/repos/actions/checkout/zipball/de0fac2e4500dabe0009e67214ff5f5447ce83dd'. Error: Response status code does not indicate success: 401 (Unauthorized). 4400:CAD68:68A901:1B6E0D1:69B23CFA

Maybe it's feeling better now?

[JelleZijlstra]

All green now, thanks to the retry fairy!

[tusharsadhwani]

I would prefer to put lazy as a keyword in pytokens instead of working around the grammar. Would you mind if I did that change on top?

[JelleZijlstra]

Go ahead!

[tusharsadhwani]

After rethinking, I am happy with doing this in black. pytokens will mimic cpython for lazy being NAME tokens.

[tusharsadhwani]

Let's merge!