Update LLM_usage.py

Changed llama model because old is deprecated

LLM_usage.py

@@ -29,7 +29,7 @@ class JokeGeneratorBot:
     ]
 
         response = completion(
-        model="groq/llama3-8b-8192", 
+        model="groq/llama-3.3-70b-versatile", 
         messages=messages,
     )
         print("Context:", context)