Update stream.dart
Update stream.dart

Fixed a typo or 2. Ran the entire file through a basic spell check and it's good now

Closes #34773
https://github.com/dart-lang/sdk/pull/34773

GitOrigin-RevId: ccde23a5880ec5904d838e5c2bc2a747c5d3ebb6
Change-Id: I154bd90376a4ea4b7a8d736382b19a44fc41e5b0
Reviewed-on: https://dart-review.googlesource.com/c/79500
Reviewed-by: Kevin Moore <1d6e7d10d051cf619c5282da3c28fd8d3e0a65a4@google.com>
Commit-Queue: Kevin Moore <1d6e7d10d051cf619c5282da3c28fd8d3e0a65a4@google.com>

dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk