This reverts commit 9967075787.
Reason for revert: Ignoring `done` is asymmetrical with other IOSinks.
Original change's description:
> [io] Fix a bug where Process.stdin.add exceptions could not be caught
>
> Change-Id: I2383a74bfa6950ab8f8934087fb68218f06dd681
> Bug:https://github.com/dart-lang/sdk/issues/48501
> Tested: Unit test
> CoreLibraryReviewExempt: dart:io only
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/351380
> Reviewed-by: Alexander Aprelev <aam@google.com>
> Commit-Queue: Brian Quinlan <bquinlan@google.com>
Bug: https://github.com/dart-lang/sdk/issues/48501
Change-Id: Ib5356c640d4dddc30e561b9d60d93f794a935103
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/359680
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Brian Quinlan <bquinlan@google.com>
97d8445e5f