inline definitions inside SchemaValidator construction

[davidhewitt]

Change Summary

This is an experiment to see what happens if definition inlining is implemented inside SchemaValidator. This should avoid the need to do it in Python (in the clean_schema function).

Hoping this has performance benefits.

Not fully implemented yet, there's some test diffs due to changes in the recursion defenses, I think I know how to resolve.

Related issue number

N/A

Checklist

• Unit tests for the changes exist
• Documentation reflects the changes where applicable
• Pydantic tests pass with this pydantic-core (except for expected changes)
• My PR is ready to review, please add a comment including the phrase "please review" to assign reviewers

[codspeed-hq]

CodSpeed Performance Report

Merging #1800 will improve performances by 31.39%

_{Comparing dh/inline-definitions (8e49e77) with main (ed0d1ca)}

Summary

⚡ 1 improvement
✅ 162 untouched

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
⚡	test_definition_out_of_tree	991.3 µs	754.5 µs	+31.39%