Merge branch '433521-disable-use_sync_service_token_worker-ff' into 'master'

Disable use_sync_service_token_worker feature flag by default

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/138746



Merged-by: Nikola Milojevic <nmilojevic@gitlab.com>
Approved-by: Nikola Milojevic <nmilojevic@gitlab.com>
Approved-by: Aleksei Lipniagov <alipniagov@gitlab.com>
Co-authored-by: Roy Zwambag <rzwambag@gitlab.com>