To avoid another surprise like we got with 3.10: https://simonwillison.net/2021/Oct/9/finding-and-reporting-a-bug/

From a quick GitHub code search it looks like 3.11-dev should work: https://cs.github.com/urllib3/urllib3/blob/7bec77e81aa0a194c98381053225813f5347c9d2/.github/workflows/ci.yml#L60