fix(parser): forbid readonly in parser instead of semantic

[ulrichstark]

Closes #13883

This also fixes duplicate essentially same diagnostics coming from parser and semantic each.

[Copilot]

Pull Request Overview

This PR moves the validation logic for readonly parameter properties from the semantic checker to the parser, preventing readonly modifiers from being parsed outside of constructor contexts rather than detecting them later during semantic analysis.

• Removes semantic validation of parameter properties outside constructors
• Updates parser to only allow readonly modifiers in constructor parameters
• Simplifies parameter validation logic by consolidating conditions

Reviewed Changes

Copilot reviewed 2 out of 5 changed files in this pull request and generated 1 comment.

File	Description
crates/oxc_semantic/src/checker/typescript.rs	Removes parameter property validation and streamlines optional parameter checking
crates/oxc_parser/src/js/function.rs	Updates modifier validation to restrict readonly to constructor contexts only

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[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #13905 will not alter performance

_{Comparing ulrichstark:forbid-readonly-in-parser-instead-of-semantic (d376144) with main (91c88e2)¹}

Summary

✅ 37 untouched

Footnotes

1. No successful run was found on main (7d45b2f) during the generation of this report, so 91c88e2 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[Boshen]

Very nice, thank you!