authz/github: org admins have read access
Created by: bobheadxi
Follow-up to https://github.com/sourcegraph/sourcegraph/pull/23978 - org admins can always see all repos in an org, regardless of default repo permission
Created by: bobheadxi
Follow-up to https://github.com/sourcegraph/sourcegraph/pull/23978 - org admins can always see all repos in an org, regardless of default repo permission