Change Choices in ChatResult to IReadOnlyList

Author: megalon

OpenAI_API/Chat/ChatResult.cs

@@ -20,7 +20,7 @@ public class ChatResult : ApiResultBase
         /// The list of choices that the user was presented with during the chat interaction
         /// </summary>
         [JsonProperty("choices")]
-        public ChatChoice[] Choices { get; set; }
+        public IReadOnlyList<ChatChoice> Choices { get; set; }
 
         /// <summary>
         /// The usage statistics for the chat interaction