Merge branch '473025-eslint-flat-config' into 'master'

Migrate to ESLint Flat Config

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/170174



Merged-by: Paul Gascou-Vaillancourt <pgascouvaillancourt@gitlab.com>
Approved-by: Jennifer Li <jli@gitlab.com>
Approved-by: Andrew Fontaine <afontaine@gitlab.com>
Reviewed-by: Paul Gascou-Vaillancourt <pgascouvaillancourt@gitlab.com>
Reviewed-by: Chaoyue Zhao <czhao@gitlab.com>
Co-authored-by: Paul Gascou-Vaillancourt <paul.gascvail@gmail.com>