Adds a specific css class to Duo chat messages that have an error so
that it can be targeted when restyling for IDE extensions.

Changelog: changed

Merge branch '499569-errors-in-duo-code-chat-in-vs-code-have-incorrect-colors-in-dark-mode' into 'main'

feat(DuoChatMessage): Add a stable CSS selector for error messages

See merge request gitlab-org/gitlab-ui!4731



Merged-by: Olena Horal-Koretska <ohoralkoretska@gitlab.com>
Approved-by: Olena Horal-Koretska <ohoralkoretska@gitlab.com>
Co-authored-by: Chad Lavimoniere <clavimoniere@gitlab.com>

# [98.4.0](gitlab-org/gitlab-ui@v98.3.0...v98.4.0) (2024-10-24)

### Features

* **DuoChatMessage:** Add a stable CSS selector for error messages ([1fe03beb](gitlab-org/gitlab-ui@1fe03beb))