Correct details about DBT_CLOUD_ENVIRONMENT_TYPE (#6509)

website/docs/docs/build/environment-variables.md

@@ -118,7 +118,7 @@ The following environment variables are set automatically:
 
 - `DBT_ENV` — This key is reserved for the dbt Cloud application and will always resolve to 'prod'. For deployment runs only.
 - `DBT_CLOUD_ENVIRONMENT_NAME` — The name of the dbt Cloud environment in which `dbt` is running. 
-- `DBT_CLOUD_ENVIRONMENT_TYPE` — The type of dbt Cloud environment in which `dbt` is running. The valid values are `development` or `deployment`.
+- `DBT_CLOUD_ENVIRONMENT_TYPE` — The type of dbt Cloud environment in which `dbt` is running. The valid values are `dev`, `staging`, or `prod`. It can be unset, so use a default like `{{env_var('DBT_CLOUD_ENVIRONMENT_TYPE', '')}}`.
 
 #### Run details