Merge branch 'ph/421630/lineCodeValidation' into 'master'

Stops tracing `line_code` when replying to a discussion

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/166299



Merged-by: Tetiana Chupryna <tchupryna@gitlab.com>
Approved-by: Tetiana Chupryna <tchupryna@gitlab.com>
Approved-by: Lukas Wanko <lwanko@gitlab.com>
Reviewed-by: Lukas Wanko <lwanko@gitlab.com>
Co-authored-by: Phil Hughes <me@iamphill.com>