Fix output property missing for airflow version < 2.4.0 (#1385)

# Description
## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->
The output was implemented in 2.4.0 according to the release notes (see
[here](https://airflow.apache.org/docs/apache-airflow/stable/release_notes.html#id13))

Add output property to MappedOperator
apache/airflow#25604

<!--
Issues are required for both bug fixes and features.
Reference it using one of the following:

closes: #ISSUE
related: #ISSUE
-->
closes: #1359 


## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

- Catch exception for airflow version < 2.4.0 and use `XComArg(...)`
instead.


## Does this introduce a breaking change?
No

### Checklist
- [x] Created tests which fail without the change (if possible)
- [x] Extended the README / documentation, if necessary

Co-authored-by: Kaxil Naik <kaxilnaik@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

python-sdk/src/astro/sql/operators/cleanup.py

@@ -232,7 +232,14 @@ def resolve_tables_from_tasks(  # noqa: C901
                     and isinstance(task, MappedOperator)
                     and issubclass(task.operator_class, OPERATOR_CLASSES_WITH_TABLE_OUTPUT)
                 ):
-                    for t in task.output.resolve(context):
+                    from airflow.models.xcom_arg import XComArg
+
+                    try:
+                        task_output = task.output
+                    except AttributeError:
+                        task_output = XComArg(operator=task)
+
+                    for t in task_output.resolve(context):
                         if isinstance(t, BaseTable):
                             res.append(t)
             except AirflowException:  # pragma: no cover