Merge branch 'ps-fix-single-file-editor-json' into 'master'

Fix single file editor not working for json files

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/147019



Merged-by: Alexander Turinske <aturinske@gitlab.com>
Approved-by: Alexander Turinske <aturinske@gitlab.com>
Co-authored-by: Paul Slaughter <pslaughter@gitlab.com>