Add CCN to the agenda (#1381)

Author: twof

agendas/2023/09-Sep/07-wg-primary.md

@@ -140,3 +140,4 @@ hold additional secondary meetings later in the month.
    - [Intro Post](https://github.com/facebook/relay/issues/4416)
 1. Changing `ExecuteSelectionSet` to `ExecuteGroupedFieldSet` (20m, Benjie)
    - [RFC](https://github.com/graphql/graphql-spec/pull/1039)
+1. Client Controlled Nullability updates (20m, Young)