stream: reject pull() reads on abort

[trivikr]

This updates stream/iter pull() so pending source reads are abort-aware.
When { signal } is provided, a pending source next() now rejects when the
signal aborts instead of waiting for the source to eventually yield.

The abort-aware wrapper returns the original source unchanged when no signal is
provided, so the normal no-signal path does not add an extra async iterator
layer.

The regression tests cover aborting while the source next() is pending in
both the no-transform path and a transform pipeline.

Fixes: #63497

---

Assisted-by: openai:gpt-5.5

[nodejs-github-bot]

Review requested:

• @nodejs/streams

[codecov]

Codecov Report

❌ Patch coverage is 95.29412% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.33%. Comparing base (a7d5446) to head (5db38ba).
⚠️ Report is 9 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/internal/streams/iter/pull.js	95.29%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #63498      +/-   ##
==========================================
+ Coverage   90.15%   90.33%   +0.17%     
==========================================
  Files         718      730      +12     
  Lines      227920   234284    +6364     
  Branches    42824    43942    +1118     
==========================================
+ Hits       205472   211629    +6157     
- Misses      14225    14377     +152     
- Partials     8223     8278      +55     

Files with missing lines	Coverage Δ
lib/internal/streams/iter/pull.js	88.33% <95.29%> (+3.18%)	⬆️

... and 84 files with indirect coverage changes

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