### Description

expanding tasks in batches to allow mapped tasks spawn more than 1024 processes.

### Use case/motivation

Maximum length of a list is limited to 1024 by `max_map_length (AIRFLOW__CORE__MAX_MAP_LENGTH)`.
during scheduling of the new tasks, an UPDATE query is ran that tries to set all the new tasks at once.  Increasing `max_map_length` more than 4K makes airflow scheduler completely unresponsive.

Also, Postgres throws `stack depth limit exceeded` error which can be fixed by updating to a newer version and setting `max_stack_depth` higher. But it doesn't really matter because airflow scheduler freezes up.
 
As a workaround, I split the dag runs into subdag runs which works but it would be much nicer if we didn't have to worry about exceeding  `max_map_length`. 

### Related issues

It was discussed here:
[Increasing 'max_map_length' leads to SQL 'max_stack_depth' error with 5000 dags to be spawned #28478](https://github.com/apache/airflow/discussions/28478)

### Are you willing to submit a PR?

- [ ] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

cls,
        dag_id: str,
        run_id: str,
        execution_date: datetime,
        session: Session = NEW_SESSION,
    ) -> DagRun | None:
        """
        Return an existing run for the DAG with a specific run_id or execution_date.
        *None* is returned if no such DAG run is found.
        :param dag_id: the dag_id to find duplicates for
        :param run_id: defines the run id for this dag run
        :param execution_date: the execution date
        :param session: database session
        """
        return (
            session.query(cls)
            .filter(
                cls.dag_id == dag_id,
                or_(cls.run_id == run_id, cls.execution_date == execution_date),
            )
            .one_or_none()
        )
    @staticmethod
    def generate_run_id(run_type: DagRunType, execution_date: datetime) -> str:
        """Generate Run ID based on Run Type and Execution Date"""
        
        return DagRunType(run_type).generate_run_id(execution_date)
    @provide_session
    def get_task_instances(