Merge branch 'fix-vite-helper-options' into 'master'

Add extname helper to match previous behavior

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/167375



Merged-by: Stanislav Lashmanov <slashmanov@gitlab.com>
Approved-by: Stanislav Lashmanov <slashmanov@gitlab.com>
Co-authored-by: Heinrich Lee Yu <heinrich@gitlab.com>