remove duplicated enums

Author: Eclairemoy

descriptions/2.11/api.intercom.io.yaml

@@ -13958,17 +13958,6 @@ components:
           - twitter
           - whatsapp
           example: conversation
-          enum:
-          - conversation
-          - email
-          - facebook
-          - instagram
-          - phone_call
-          - phone_switch
-          - push
-          - sms
-          - twitter
-          - whatsapp
         id:
           type: string
           description: The id representing the message.