port Python::eval to Bound API

[Icxolu]

Part of #3684 and split from #3716

This converts to the Python::eval function to the new API. For easier reviewing this focuses purely on eval/eval_bound and leaves the very similar Python::run method as well as the PyDict methods for followup PRs.

[codspeed-hq]

CodSpeed Performance Report

Merging #3806 will degrade performances by 15.63%

_{Comparing Icxolu:python-eval (33dc33e) with main (9bb0011)}

Summary

⚡ 1 improvements
❌ 3 regressions
✅ 75 untouched benchmarks

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

Benchmarks breakdown

	Benchmark	main	Icxolu:python-eval	Change
❌	list_via_downcast	157.2 ns	185 ns	-15.02%
⚡	not_a_list_via_downcast	272.2 ns	244.4 ns	+11.36%
❌	sequence_from_tuple	232.8 ns	260.6 ns	-10.66%
❌	sequence_from_list	300 ns	355.6 ns	-15.63%

[davidhewitt]

Sorry for the slight delay, I will do my best to review this tonight.

[davidhewitt]

Fantastic, this is a much more reviewable first step. Thanks again and sorry I was a bit stretched for time in the last couple of days!

[davidhewitt]

👍 very tidy temporary solution!

[davidhewitt]

Uff rust nightly change broke the merge.

[Icxolu]

Rebased, to include CI fixes

[davidhewitt]

👍 sorry I forgot to rerun the merge queue, it should have automatically picked them up but I just got sidetracked.