input: Write a function to create a Celery task in Python to send an email. The function should be named `create_email_task` and take four parameters: `recipient_name`, `recipient_email`, `subject`, and `message`. It should return the Celery task that sends the email.
  assert create_email_task('John Smith', 'john@example.com', 'Hello World', 'This is a test email.') == <Celery task to send email>
  assert create_email_task('Jane Doe', 'jane@example.com', 'Important Notice', 'Please read this.') == <Celery task to send email>
  assert create_email_task('Alice', 'alice@example.com', 'Reminder', 'Don't forget the meeting.') == <Celery task to send email>
  assert create_email_task('Bob', 'bob@example.com', 'Greetings', 'Hello, Bob!') == <Celery task to send email>
  assert create_email_task('', '', '', '') == <Celery task to send email>
output: def create_email_task(recipient_name, recipient_email, subject, message):
      from celery import Celery
      app = Celery('tasks', broker='pyamqp://guest@localhost//')
  
      @app.task
      def send_email(name, email, subj, msg):
          # Dummy implementation of sending email
          pass
  
      return send_email.s(recipient_name, recipient_email, subject, message)