Description:

Disable cache: 'pip' for unreleased Python versions (right now, that means only Python 3.11)

Justification:

The ABI between Python 3.11 versions is not stable, and in fact recently changed between Python 3.11 alpha 2 and alpha 3. This is why projects don't provide binary wheels for Python 3.11 until the ABI is stabilized. Unfortunately, when enabling pip's cache, this means that wheels cached for Python 3.11 alpha 2 will get used for Python 3.11 alpha 3 and are then likely to break or segfault. This is not a theoretical concern, this broke urllib3's test suite, and likely cryptography's test suite as well. See https://bugs.python.org/issue46320 for more details.

Without this change, our options are disabling pip's cache altogether or stop testing Python 3.11.

Are you willing to submit a PR?

No, sorry.