Merge branch 'ld-docs-graphql-global-id-clarifications' into 'master'

Clarify use of Global IDs in customer GraphQL docs

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/138856



Merged-by: Evan Read <eread@gitlab.com>
Approved-by: charlie ablett <cablett@gitlab.com>
Co-authored-by: Luke Duncalfe <lduncalfe@gitlab.com>
Co-authored-by: charlie ablett <cablett@gitlab.com>
Co-authored-by: Luke Duncalfe <lduncalfe@eml.cc>