Fix docs typo.
Fix docs typo.

Closes https://github.com/dart-lang/sdk/pull/41753
https://github.com/dart-lang/sdk/pull/41753

GitOrigin-RevId: 38fcff0d4687c76d0ae1ab0cf18ade4b29e42788
Change-Id: I67b768ee32de0c1d8741b40880f16d018656c734
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/146140
Reviewed-by: Michael Thomsen <5977a55c75bb4612004451a56b0b4c22d9d3311d@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk