add bound constructors for PySet and PyFrozenSet

[davidhewitt]

Implements new_bound for PySet and PyFrozenSet, adding the deprecations to new and updating relevant internal code.

[codspeed-hq]

CodSpeed Performance Report

Merging #3743 will degrade performances by 10.44%

_{Comparing davidhewitt:set-bound-constructors (4e24e68) with main (43504cd)}

Summary

⚡ 3 improvements
❌ 1 regressions
✅ 74 untouched benchmarks

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

Benchmarks breakdown

	Benchmark	main	davidhewitt:set-bound-constructors	Change
❌	extract_int_downcast_fail	238.3 ns	266.1 ns	-10.44%
⚡	iter_set	51.9 ms	40.7 ms	+27.41%
⚡	not_a_list_via_downcast	153.9 ns	126.1 ns	+22.03%
⚡	list_via_downcast	153.9 ns	126.1 ns	+22.03%

[davidhewitt]

Unless anyone feels a strong desire to review this one, I might merge this and also #3755 in the near future, as both are mechanical changes just following the patterns we've already established on how we want these new_bound APIs to be like for now.

[adamreichold]

The diff is a bit messy, but the result looks good to me.

[davidhewitt]

Thanks! Yes, I think quite a few of these PRs adding / deprecating constructors are touching quite a few bits of the codebase. It's going to be a relief to tidy these up again in the future.