port Python::get_type to Bound API

[Icxolu]

Part of #3684

This ports Python::get_type to the Bound API. I implemented this on a rebase of #3705 (with minor changes to adapt for changes since creation), so this should compile already. All the changes related to the get_type conversion are in a separate commit. I'll mark this as draft and rebase this when #3705 lands.

[codspeed-hq]

CodSpeed Performance Report

Merging #3846 will degrade performances by 10.2%

_{Comparing Icxolu:get-type (4b88d8e) with main (f04ad56)}

Summary

⚡ 4 improvements
❌ 1 regressions
✅ 74 untouched benchmarks

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

Benchmarks breakdown

	Benchmark	main	Icxolu:get-type	Change
⚡	extract_float_extract_success	500.6 ns	445 ns	+12.48%
⚡	extract_str_downcast_success	728.9 ns	645.6 ns	+12.91%
⚡	list_via_extract	364.4 ns	308.9 ns	+17.99%
❌	not_a_list_via_downcast	244.4 ns	272.2 ns	-10.2%
⚡	sequence_from_tuple	267.2 ns	239.4 ns	+11.6%

[davidhewitt]

Great, many thanks! I think #3705 is finally in a good state to review again, after a long deviation to get #3831 done first...

[Icxolu]

Rebased

[LilyFoote]

Looks good to me!

[davidhewitt]

Thanks, overall looks great! Got a suggestion for the FIXME...

[davidhewitt]

I think you're looking for Py::new or Bound::new, I guess we should deprecate PyCell::newin favour of one of these.

[Icxolu]

Ah, nice and easy! (And thanks for catching, I totally forget that i put that there)

I guess we should deprecate PyCell::new in favour of one of these.

That's a good idea, I'll look into that 👍

[davidhewitt]

Perfect, thanks!