Only check non-parent monomorphization args

[xunilrj]

Description

This PR fixes #6384

The performance improvement is probably coming from just aggregating spans when there is an error.

Checklist

• I have linked to any relevant issues.
• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation where relevant (API docs, the reference, and the Sway book).
  • If my change requires substantial documentation changes, I have requested support from the DevRel team
• I have added tests that prove my fix is effective or that my feature works.
• I have added (or requested a maintainer to add) the necessary Breaking* or New Feature labels where relevant.
• I have done my best to ensure that my PR adheres to the Fuel Labs Code Review Standards.
• I have requested a review from the relevant team or maintainers.

[codspeed-hq]

CodSpeed Performance Report

Merging #6549 will improve performances by 18.83%

_{Comparing xunilrj/check-monomorphization-non-parent-only (0705c89) with master (520bfe9)}

Summary

⚡ 1 improvements
✅ 21 untouched benchmarks

Benchmarks breakdown

	Benchmark	master	xunilrj/check-monomorphization-non-parent-only	Change
⚡	inlay_hints	3.8 ms	3.2 ms	+18.83%