stream: fix ERR_INVALID_STATE when cancelling Readable.toWeb()

[richardscarrott]

When a web ReadableStream returned by Readable.toWeb() is cancelled while the underlying Readable is actively producing data, a pending onData callback can still fire after the controller has been closed and attempt to enqueue a chunk, throwing ERR_INVALID_STATE.

Check wasCanceled in the onData handler and return early to avoid calling controller.enqueue() on a closed controller.

Refs: #54205

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.69%. Comparing base (ed05549) to head (96e546b).
⚠️ Report is 13 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #62773   +/-   ##
=======================================
  Coverage   89.69%   89.69%           
=======================================
  Files         706      706           
  Lines      218127   218144   +17     
  Branches    41734    41743    +9     
=======================================
+ Hits       195651   195669   +18     
+ Misses      14400    14396    -4     
- Partials     8076     8079    +3     

Files with missing lines	Coverage Δ
lib/internal/webstreams/adapters.js	86.61% <100.00%> (+0.01%)	⬆️

... and 41 files with indirect coverage changes

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[efekrskl]

Thank you for your contribution @richardscarrott!

Could you please fix the linting errors?

[smoores-dev]

Howdy folks! I think we're running into this as well — @richardscarrott if you don't have time to take this over the finish line, happy to take it over and fix the linting errors!

[richardscarrott]

@smoores-dev @efekrskl soz, forgot about this. I have some time tomorrow to fix this up.

[richardscarrott]

Rebased onto main and fixed the lint error.

Worth flagging for re-review: #62394 rewrote newReadableStreamFromStreamReadable after this PR was opened, so the patch needed porting — the onData logic now lives in an inline 'data' listener. I confirmed the race is still present on current main; without the guard, test-stream-readable-to-web-termination.js fails with:

TypeError [ERR_INVALID_STATE]: Invalid state: Controller is already closed
    at ReadableStreamDefaultController.enqueue (node:internal/webstreams/readablestream:1189:13)
    at Readable.onData (node:internal/webstreams/adapters:547:18)
    at flow (node:internal/streams/readable:1319:53)
    at resume_ (node:internal/streams/readable:1295:3)

Note this is the enqueue path, distinct from the close path in #54205 (which #54206 already fixed) — hence Refs: rather than Fixes:. Upstream's rewritten test file is preserved as-is with the new case appended.

@meixg your approval predates the rebase, so this likely needs another look.