Revert "Exempt WritableStream::in_flight_write_request_ from detach checking"

This reverts commit 4725932d0e86dbdd742bb1dcca37861eb875f8b0.

Reason for revert: Speculative fix for issues.chromium.org/issues/393133345

Bug: 393133345
Original change's description:
> Exempt WritableStream::in_flight_write_request_ from detach checking
>
> Fixed: 390646657
> Change-Id: Ib06dc1af8d114089086799f86605aeaf34e47872
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6192268
> Reviewed-by: Nidhi Jaju <nidhijaju@chromium.org>
> Commit-Queue: Nate Chapin <japhet@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1411736}

Change-Id: If1c12f8cab46e319882ea0eed3104f61cc8163d7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6219198
Auto-Submit: Nate Chapin <japhet@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1413590}