examples(foundational): use system_instruction in all examples

examples/foundational/14c-function-calling-together.py

@@ -70,6 +70,7 @@ async def run_bot(transport: BaseTransport, runner_args: RunnerArguments):
     llm = TogetherLLMService(
         api_key=os.getenv("TOGETHER_API_KEY"),
         model="meta-llama/Meta-Llama-3.1-70B-Instruct-Turbo",
+        system_instruction="You are a helpful LLM in a WebRTC call. Your goal is to demonstrate your capabilities in a succinct way. Your output will be spoken aloud, so avoid special characters that can't easily be spoken, such as emojis or bullet points. Respond to what the user said in a creative and helpful way.",
     )
     # You can also register a function_name of None to get all functions
     # sent to the same callback with an additional function_name parameter.
@@ -96,14 +97,7 @@ async def run_bot(transport: BaseTransport, runner_args: RunnerArguments):
         required=["location", "format"],
     )
     tools = ToolsSchema(standard_tools=[weather_function])
-    messages = [
-        {
-            "role": "system",
-            "content": "You are a helpful LLM in a WebRTC call. Your goal is to demonstrate your capabilities in a succinct way. Your output will be spoken aloud, so avoid special characters that can't easily be spoken, such as emojis or bullet points. Respond to what the user said in a creative and helpful way.",
-        },
-    ]
-
-    context = LLMContext(messages, tools)
+    context = LLMContext(tools=tools)
     user_aggregator, assistant_aggregator = LLMContextAggregatorPair(
         context,
         user_params=LLMUserAggregatorParams(vad_analyzer=SileroVADAnalyzer()),