### 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)

run_id = self.run_id
        try:
            if hook_is_noop:
                session.bulk_insert_mappings(TI, tasks)
            else:
                session.bulk_save_objects(tasks)
            for task_type, count in created_counts.items():
                Stats.incr(f"task_instance_created-{task_type}", count, tags=self.stats_tags)
            session.flush()
        except IntegrityError:
            self.log.info(
                "Hit IntegrityError while creating the TIs for %s- %s",
                dag_id,
                run_id,
                exc_info=True,
            )
            self.log.info("Doing session rollback.")
            
            session.rollback()
    def _revise_map_indexes_if_mapped(self, task: Operator, *, session: Session) -> Iterator[TI]:
        """Check if task increased or reduced in length and handle appropriately.
        Task instances that do not already exist are created and returned if
        possible. Expansion only happens if all upstreams are ready; otherwise
        we delay expansion to the "last resort". See comments at the call site
        for more details.
        """
        from airflow.settings import task_instance_mutation_hook
        try:
            total_length = task.get_mapped_ti_count(self.run_id, session=session)
        except NotMapped: