check duplicate object keys

[samuelcolvin]

Optionally check for duplicate keys in python_parse.

[codspeed-hq[bot]]

CodSpeed Performance Report

Merging #81 will degrade performances by 21.04%

_{Comparing check-duplicate-keys (c350499) with main (75699eb)}

Summary

❌ 1 regressions ✅ 72 untouched benchmarks

:warning: Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	check-duplicate-keys	Change
❌	pass2_jiter_skip	5.5 µs	7 µs	-21.04%

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

:loudspeaker: Thoughts on this report? Let us know!

[davidhewitt]

Bench change doesn't look significant, maybe an inlining change in Rust 1.78. I think the skip functions can probably avoid recursion so I'll try to transform them next week and optimise them that way 😄