parse dagrun_timeout as a timedelta instead of int

[kiranvasudev]

DATA-2387

After upgrading to Airflow 2.11, there is more strict type checks that are performed.

As a result, when we use dagrun_timeout, like here the dags fail to load on airflow because dagrun_timeout expects a timedelta but we input an int.

As a quick fix, I use the eval method to evaluate the input dagrun_timeout, provided that the value we input is something like "timedelta(seconds=1500)". you can see this here.