fivetran/dbt_hubspot_source

AI Summary: This task requires updating a dbt model and associated files to support a new `is_closed` column in the HubSpot deal pipeline stage data, while maintaining backward compatibility with the existing `closed_won` column. This involves modifying a SQL model to use `COALESCE`, updating a macro to include the new column, documenting the change in the source YAML file, and adding the new column to a test CSV file.