Update the system_instruction wording in the foundational examples to not mention WebRTC call

examples/foundational/07b-interruptible-langchain.py

@@ -80,8 +80,7 @@ async def run_bot(transport: BaseTransport, runner_args: RunnerArguments):
         [
             (
                 "system",
-                "Be nice and helpful. Answer very briefly and without special characters like `#` or `*`. "
-                "Your response will be synthesized to voice and those characters will create unnatural sounds.",
+                "You are a helpful assistant in a voice conversation. Your responses will be spoken aloud, so avoid emojis, bullet points, or other formatting that can't be spoken. Respond to what the user said in a creative, helpful, and brief way.",
             ),
             MessagesPlaceholder("chat_history"),
             ("human", "{input}"),