update redshift connection id to be consistent (#960)

Author: eakmanrq

docs/integrations/engines.md

@@ -251,7 +251,7 @@ By default, the connection ID is set to `sqlmesh_redshift_default`, but it can b
 sqlmesh_airflow = SQLMeshAirflow(
     "redshift",
     engine_operator_args={
-        "conn_id": "<Connection ID>"
+        "redshift_conn_id": "<Connection ID>"
     },
 )
 ```

sqlmesh/schedulers/airflow/operators/redshift.py

@@ -14,15 +14,16 @@ class SQLMeshRedshiftOperator(BaseSQLOperator):
 
     Args:
         target: The target that will be executed by this operator instance.
-        conn_id: The Airflow connection id for the Redshift target.
+        redshift_conn_id: The Airflow connection id for the Redshift target.
     """
 
     def __init__(
         self,
         target: BaseTarget,
+        redshift_conn_id: str = SQLMeshRedshiftHook.default_conn_name,
         **kwargs: t.Any,
     ) -> None:
-        super().__init__(conn_id=SQLMeshRedshiftHook.default_conn_name, **kwargs)
+        super().__init__(conn_id=redshift_conn_id, **kwargs)
         self._target = target
 
     def get_db_hook(self) -> SQLMeshRedshiftHook: