Signaling data availability with an Asset outlet

Your team has a pipeline that writes daily sales data to s3://data-lake/sales/daily.csv, and several downstream pipelines depend on it. Instead of having them poll on a timer or guess when the file is ready, you'll attach an Asset outlet so this task signals that the data was updated the moment it finishes. That signal is what lets other Dags schedule themselves on the data itself.

After completing the code, run the file, then verify the asset was registered and updated using the Airflow CLI.