Merge branch 'add_ff_to_allow_editing_of_synced_epic_work_item' into 'master'

Reverse make_synced_work_item_read_only FF check logic

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/156648



Merged-by: Felipe Artur <fcardozo@gitlab.com>
Approved-by: Jarka Košanová <jarka@gitlab.com>
Approved-by: Felipe Artur <fcardozo@gitlab.com>
Reviewed-by: Felipe Artur <fcardozo@gitlab.com>
Co-authored-by: Alexandru Croitor <acroitor@gitlab.com>