fix: remove maxTokens for gpt-5 (#8843)

Co-authored-by: Chandrapal Badshah <12944530+Chan9390@users.noreply.github.com>

ui/lib/lighthouse/utils.ts

@@ -46,6 +46,7 @@ export const getModelParams = (config: any): ModelParams => {
   if (modelId.startsWith("gpt-5")) {
     params.temperature = undefined;
     params.reasoningEffort = "minimal" as const;
+    params.maxTokens = undefined;
   }
 
   return params;