message: docs(sample): remove repeated code
diff: @@ -46,11 +46,6 @@ function main(
  const pubSubClient = new PubSub();
  async function publishMessage() {
  - /**
  - * TODO(developer): Uncomment the following lines to run the sample.
  - */
  - // const topicName = 'my-topic';
  -
  // Publishes the message as a string, e.g. "Hello, world!" or JSON.stringify(someObject)
  const dataBuffer = Buffer.from(data);
  