fix: chat stream resp error (#259)

chat_stream.go

@@ -3,6 +3,7 @@ package openai
 import (
 	"bufio"
 	"context"
+	"net/http"
 )
 
 type ChatCompletionStreamChoiceDelta struct {
@@ -53,6 +54,9 @@ func (c *Client) CreateChatCompletionStream(
 	if err != nil {
 		return
 	}
+	if resp.StatusCode < http.StatusOK || resp.StatusCode >= http.StatusBadRequest {
+		return nil, c.handleErrorResp(resp)
+	}
 
 	stream = &ChatCompletionStream{
 		streamReader: &streamReader[ChatCompletionStreamResponse]{