Merge branch 'docs-external-status-check' into 'master'

Use the word "service" consistently for external status check

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/116778



Merged-by: Evan Read <eread@gitlab.com>
Approved-by: Evan Read <eread@gitlab.com>
Approved-by: Nathan Rosandich <nrosandich@gitlab.com>
Co-authored-by: Jeremie Bresson <jeremie.bresson@unblu.com>