Merge branch 'rodrigo/fix-undefined-start_with-error' into 'master'

Fix markdown import attachments in GitHub Import

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/106459



Merged-by: Ethan Urie <eurie@gitlab.com>
Approved-by: Rostyslav Safonov <elhowm@gmail.com>
Approved-by: Ethan Urie <eurie@gitlab.com>
Co-authored-by: Rodrigo Tomonari <rtomonari@gitlab.com>