wip test PyO3 HEAD

[davidhewitt]

PyO3 head contains some breaking changes and perf tweaks; I want to get early visibility onto those.

[codspeed-hq]

CodSpeed Performance Report

Merging #1450 will degrade performances by 25.18%

_{Comparing dh/pyo3-0.23 (5e6b595) with main (6472887)}

Summary

❌ 4 regressions
✅ 151 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	dh/pyo3-0.23	Change
❌	test_enum_int_core	15.2 µs	20.2 µs	-24.49%
❌	test_enum_str_core	14.8 µs	19.7 µs	-25.18%
❌	test_json_any_list_int	195.3 µs	222.7 µs	-12.33%
❌	test_to_json_list_of_lists	1.7 ms	2 ms	-15.16%

[davidhewitt]

Performance diffs do not seem concerning to me; clicking through to codspeed there is a mix of positive and negative changes to about the same scale. Serialization was probably impacted slightly negatively due to the addition of the mutexes here.

PyO3 0.23 is a fairly big change due to freethreaded Python support so the fact there's no particularly big perf change here is a success in my eyes; we believe that future PyO3 versions will be able to optimize following the big changes of 0.23.

[davidhewitt]

This is getting big enough that I'm going to halt here; I'm just doing mechanical changes so I'm convinced the upgrade is ok. Will continue it after PyO3 0.23 actually released.

When we merge, will probably do it in phases to make it reviewable.

[davidhewitt]

All is now merged into main, with last piece at #1584