Merge branch '441159-fix-line-anchors' into 'master'

Fix line anchor hrefs for legacy viewers

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/144340



Merged-by: Zack Cuddy <zcuddy@gitlab.com>
Approved-by: Zack Cuddy <zcuddy@gitlab.com>
Co-authored-by: Jacques <jerasmus@gitlab.com>