Please update PyO3 to 0.20.3 and make a new release

[mgorny]

The current PyO3 version of 0.20.2 is broken on PowerPC (PyO3/pyo3@9d1b11f). This is preventing PowerPC users from receiving the security fix from cryptography-42.0.4.

Could you update PyO3 and make a new release, please?

[alex]

We merged the pyo3 change into main -- and it should be trivial to cherry-pick. @reaperhulk and I can talk about a backport+release

[alex]

Ok, both of us are good with doing a backport. We're going to see if there's other stuff we want to backport, but aim to get this out today or tomorrow I think.

[mgorny]

Thanks a lot!

[reaperhulk]

#10465 is the backport

[alex]

Done