Cleanup unused code after move to React Executor

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/169951



Merged-by: Kassio Borges <kborges@gitlab.com>
Approved-by: Manoj M J <mmj@gitlab.com>
Approved-by: Kassio Borges <kborges@gitlab.com>
Co-authored-by: Tetiana Chupryna <tchupryna@gitlab.com>