Make sure new CSS compiler respects HMR setting

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/144481



Merged-by: Paul Gascou-Vaillancourt <pgascouvaillancourt@gitlab.com>
Approved-by: Paul Gascou-Vaillancourt <pgascouvaillancourt@gitlab.com>
Co-authored-by: Lukas Eipert <leipert@gitlab.com>