fix(fetch): reject forbidden HTTP methods CONNECT, TRACE, and TRACK

[HiteshShonak]

This Pull Request fixes/closes #5202.

It changes the following:

• Reject CONNECT, TRACE, and TRACK methods in the Request constructor and throw a TypeError, matching the Fetch Standard.
• Check is case-insensitive, so connect, trace, track are also rejected.
• Added regression tests for all three forbidden methods.

Testing:

cargo test -p boa_runtime request -- --nocapture

Spec reference: https://fetch.spec.whatwg.org/#forbidden-method

[Copilot]

Pull request overview

This PR updates Boa’s Fetch Request implementation to match the Fetch Standard by rejecting forbidden HTTP methods (CONNECT, TRACE, TRACK) in the Request constructor path, and adds regression tests to prevent the behavior from regressing.

Changes:

• Reject CONNECT/TRACE/TRACK (case-insensitive) in RequestInit::into_request_builder by throwing a TypeError.
• Add regression tests asserting new Request(..., { method }) throws for each forbidden method.
• Add indoc usage in request tests for cleaner embedded JS snippets.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
core/runtime/src/fetch/request.rs	Adds forbidden-method validation during request builder construction, returning a TypeError for CONNECT/TRACE/TRACK.
core/runtime/src/fetch/tests/request.rs	Adds new tests ensuring Request construction throws when using forbidden methods.

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[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	52,963	52,963	0
Passed	50,539	50,539	0
Ignored	1,426	1,426	0
Failed	998	998	0
Panics	2	2	0
Conformance	95.42%	95.42%	0.00%

Tested main commit: 58a24587890677d94618259dfaa5f257ab5ef9c9
Tested PR commit: 3190e5e6986b17df1c4e23dce597f413388bd3d8
Compare commits: 58a2458...3190e5e

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 59.81%. Comparing base (6ddc2b4) to head (3190e5e).
⚠️ Report is 913 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #5203       +/-   ##
===========================================
+ Coverage   47.24%   59.81%   +12.56%     
===========================================
  Files         476      582      +106     
  Lines       46892    63466    +16574     
===========================================
+ Hits        22154    37961    +15807     
- Misses      24738    25505      +767     

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