GraphQL: runners query is only available to administrators but documentation implies otherwise
https://docs.gitlab.com/ee/api/graphql/reference/#queryrunners says that the call finds "runners visible to the current user". It should specify that this query is only available to administrators. It is possible for non-admins to retrieve runners, but only in the context of a group or a project.
We should update the documentation to reflect the limitation, and also possibly return an error when the user is not an admin.