Add 2.16 to the Intercom-Version enum in the Preview description (#630)

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: VarshSuresh

descriptions/0/api.intercom.io.yaml

@@ -37658,6 +37658,7 @@ components:
       - '2.13'
       - '2.14'
       - '2.15'
+      - '2.16'
       - Preview
     linked_object:
       title: Linked Object