cleanup: remove auxilary return for now (#1727)

Author: Salazareo

src/backend/src/modules/puterai/lib/OpenAIUtil.js

@@ -91,7 +91,6 @@ const extractMeteredUsage = (usage) => {
 const create_chat_stream_handler = ({
     deviations,
     completion,
-    usage_calculator,
     usage_promise,
 }) => async ({ chatStream }) => {
     deviations = Object.assign({
@@ -161,10 +160,6 @@ const create_chat_stream_handler = ({
     if ( mode === 'tool' ) toolblock.end();
     message.end();
     chatStream.end();
-    return usage_calculator ? usage_calculator({ usage: last_usage }) : {
-        input_tokens: last_usage.prompt_tokens,
-        output_tokens: last_usage.completion_tokens,
-    };
 };
 
 /**