Fix examples

examples/foundational/07z-interruptible-sarvam-http.py

@@ -73,7 +73,7 @@ async def run_bot(transport: BaseTransport, runner_args: RunnerArguments):
         )
 
         llm = SarvamLLMService(
-            api_key=os.getenv("OPENAI_API_KEY"),
+            api_key=os.getenv("SARVAM_API_KEY"),
             settings=SarvamLLMService.Settings(
                 system_instruction="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.",
             ),