### 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)

schedulable_tis, callback_to_run = dag_run.update_state(session=session, execute_callbacks=False)
        if dag_run.state in State.finished:
            active_runs = dag.get_num_active_runs(only_running=False, session=session)
            
            if self._should_update_dag_next_dagruns(dag, dag_model, active_runs):
                dag_model.calculate_dagrun_date_fields(dag, dag.get_run_data_interval(dag_run))
        
        
        
        
        dag_run.schedule_tis(schedulable_tis, session)
        return callback_to_run
    def _verify_integrity_if_dag_changed(self, dag_run: DagRun, session: Session) -> bool:
        """
        Only run DagRun.verify integrity if Serialized DAG has changed since it is slow.
        Return True if we determine that DAG still exists.
        """
        latest_version = SerializedDagModel.get_latest_version_hash(dag_run.dag_id, session=session)
        if dag_run.dag_hash == latest_version:
            self.log.debug("DAG %s not changed structure, skipping dagrun.verify_integrity", dag_run.dag_id)
            return True
        dag_run.dag_hash = latest_version
        
        dag_run.dag = self.dagbag.get_dag(dag_id=dag_run.dag_id, session=session)
        if not dag_run.dag:
            return False
        
        dag_run.verify_integrity(session=session)
        return True
    def _send_dag_callbacks_to_processor(self, dag: DAG, callback: DagCallbackRequest | None = None) -> None: