Merge branch 'job-token-setting-help-text' into 'master'

Update help text for job token setting

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/160523



Merged-by: Mireya Andres <mandres@gitlab.com>
Approved-by: Bonnie Tsang <btsang@gitlab.com>
Approved-by: Mireya Andres <mandres@gitlab.com>
Reviewed-by: Bonnie Tsang <btsang@gitlab.com>
Co-authored-by: Marcel Amirault <mamirault@gitlab.com>