[ VM / dart:io ] Update documentation for  to warn '--pause-isolates-on-exit' is not respected when `exit` is called
[ VM / dart:io ] Update documentation for  to warn '--pause-isolates-on-exit' is not respected when `exit` is called

Fixes issue #31747

Change-Id: Id8a5504f5a13c056a8f366e49be3f6e21652a649
Reviewed-on: https://dart-review.googlesource.com/c/89182
Reviewed-by: Siva Annamalai <2e618a8cbd7bb6b3d4409061ae407d692a098546@google.com>
Commit-Queue: Siva Annamalai <2e618a8cbd7bb6b3d4409061ae407d692a098546@google.com>
Auto-Submit: Ben Konyi <67ffcaedcc3dc3d87dddb9627b72dd41756b31b1@google.com>

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