updated the model to openai

src/service.py

@@ -80,7 +80,7 @@ prompt = ChatPromptTemplate.from_messages(
 )
 
 llm = ChatGroq(
-    model="llama-3.1-8b-instant",
+    model="openai/gpt-oss-120b",
     temperature=0.5,
     max_tokens=1000,
     api_key=groq_api_key