feat(api): add chatgpt-4o-latest model

Author: stainless-bot

src/resources/chat/completions.ts

@@ -475,7 +475,7 @@ export interface ChatCompletionMessage {
    * @deprecated: Deprecated and replaced by `tool_calls`. The name and arguments of
    * a function that should be called, as generated by the model.
    */
-  function_call?: ChatCompletionMessage.FunctionCall;
+  function_call?: ChatCompletionMessage.FunctionCall | null;
 
   /**
    * The tool calls generated by the model, such as function calls.