Merge branch 'ch_remove-unused-web-ide-ff' into 'master'

Remove unused settings sync feature flag from Web IDE config

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/170852



Merged-by: Paul Slaughter <pslaughter@gitlab.com>
Approved-by: Paul Slaughter <pslaughter@gitlab.com>
Co-authored-by: Cindy Halim <chalim@gitlab.com>