Add skip_notifications to conversations reply endpoint

Adds support for the skip_notifications parameter on the Conversations API
reply endpoint (POST /conversations/{id}/reply) in the unstable spec.

This brings parity with the Tickets API which already supports this parameter.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: markdennis22

descriptions/0/api.intercom.io.yaml

@@ -7394,7 +7394,15 @@ paths:
         content:
           application/json:
             schema:
-              "$ref": "#/components/schemas/reply_conversation_request"
+              oneOf:
+              - "$ref": "#/components/schemas/contact_reply_conversation_request"
+              - "$ref": "#/components/schemas/admin_reply_conversation_request"
+              properties:
+                skip_notifications:
+                  type: boolean
+                  description: Option to disable notifications when replying to a
+                    conversation.
+                  example: true
             examples:
               user_reply:
                 summary: User reply