In ChatGPT mode use newer model by default

Author: artyom

chatgpt.go

@@ -70,7 +70,7 @@ func chatgpt(ctx context.Context, args runArgs) error {
 	userMessage.Content = append(userMessage.Content, textBlock(prompt))
 
 	modelRequest := chatgptRequest{
-		Model:  cmp.Or(os.Getenv("LLMCLI_CHATGPT_MODEL"), "gpt-4o"),
+		Model:  cmp.Or(os.Getenv("LLMCLI_CHATGPT_MODEL"), "gpt-4o-2024-08-06"),
 		Stream: true,
 		Messages: []message{
 			{Role: "system", Content: []contentEntry{textBlock(systemPrompt)}},