[roll] Roll fuchsia Revert "[debug][DAP] Flush BufferedFD stream before EOF teardown"

This reverts commit 33d22639120d19a887cdb3e1ee146080d9ae8580.

Reason for revert: Introduced flakiness: b/519848896

Original change's description:
> [debug][DAP] Flush BufferedFD stream before EOF teardown
>
> Fixes a bug in BufferedFD::OnFDReady where the reader was not notified
> of the final read data if EOF was received in the same event cycle.
>
> This bug was exposed by the VS Code Fuchsia extension during test success
> teardowns: VS Code sends a "disconnect" request and then closes the socket.
> Due to a hang in zxdb, the request sat unread. When VS Code closed the socket,
> the OS sent a TCP Reset. BufferedFD read the reset EOF in the same tick but
> exited early, discarding the "disconnect" request without notifying the parser,
> leaving the C++ zxdb process orphaned in the background.
>
> Fixed by synchronously invoking the callback on EOF to drain the stream
> before calling OnFDError().
>
> Original-Bug: 518607183
> Cq-Include-Trybots: luci.fuchsia.try:core.x64-debug
> Change-Id: Ie83eccbb6e4cb60a9527b7498e4acd35b27fa6b9
> Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1634034
> Reviewed-by: Jacob Rutherford <jruthe@google.com>
> Commit-Queue: Dorian Lee <dorianlee@google.com>

Original-Original-Bug: 518607183
Original-Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1639514
Exempt: android-build-ayeaye@system.gserviceaccount.com <android-build-ayeaye@system.gserviceaccount.com>
Original-Original-Revision: 6d20aee7f74d403a41a5fee35025e5ba71631f1a
GitOrigin-RevId: 49643124d6d91234cdd261e9a389cc4d0bde74c6
Change-Id: Ib07ccd3a5c09a2941b55548f1613eaf41459b79b
Reviewed-on: https://fuchsia-review.googlesource.com/c/integration/+/1639539
Cr-Commit-Position: refs/heads/main@{#194104}