Update airflow-db-cleanup.py to work with airflow 2.x

[nukima]

This should work with airflow 2.x (tested with 2.3.4)

[arms23]

Is this project still alive ? Was it replaced by something else ?

[NatLee]

This may occur ercursion error tested in 2.9.0 with image apache/airflow:slim-2.9.0-python3.9.

  File "/home/airflow/.local/lib/python3.9/site-packages/sqlalchemy/sql/type_api.py", line 1497, in __getattr__
    return getattr(self.impl, key)
  File "/home/airflow/.local/lib/python3.9/site-packages/sqlalchemy/sql/type_api.py", line 1497, in __getattr__
    return getattr(self.impl, key)
  File "/home/airflow/.local/lib/python3.9/site-packages/sqlalchemy/sql/type_api.py", line 1497, in __getattr__
    return getattr(self.impl, key)
  [Previous line repeated 4896 more times]
RecursionError: maximum recursion depth exceeded