fix(instrumentation-fetch): do not consume Request before ignoreUrls

[BetterAndBetterII]

Fixes #7037. Delay Request clone until after the ignoreUrls span check so fetch(Request, init) does not throw on ignored URLs.

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[BetterAndBetterII]

ignoreUrls is now checked first, and _createSpan runs after new Request, so a constructor throw cannot leave a span open. Added a regression test for that path.

[codecov]

Codecov Report

❌ Patch coverage is 75.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 94.97%. Comparing base (82a5831) to head (da22748).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
...s/opentelemetry-instrumentation-fetch/src/fetch.ts	75.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7038      +/-   ##
==========================================
- Coverage   94.99%   94.97%   -0.03%     
==========================================
  Files         409      409              
  Lines       14338    14344       +6     
  Branches     3280     3284       +4     
==========================================
+ Hits        13621    13623       +2     
- Misses        717      721       +4     

Files with missing lines	Coverage Δ
...s/opentelemetry-instrumentation-fetch/src/fetch.ts	81.81% <75.00%> (-1.36%)	⬇️

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[JacksonWeber]

Could we pass options to _createSpan here? Reading args[1].method again can trigger getters twice and cause unexpected errors.