### 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)

from airflow.utils import timezone
from airflow.utils.context import ConnectionAccessor, Context, VariableAccessor, context_merge
from airflow.utils.email import send_email
from airflow.utils.helpers import prune_dict, render_template_to_string
from airflow.utils.log.logging_mixin import LoggingMixin
from airflow.utils.module_loading import qualname
from airflow.utils.net import get_hostname
from airflow.utils.operator_helpers import context_to_airflow_vars
from airflow.utils.platform import getuser
from airflow.utils.retries import run_with_db_retries
from airflow.utils.session import NEW_SESSION, create_session, provide_session
from airflow.utils.sqlalchemy import (
    ExecutorConfigType,
    ExtendedJSON,
    UtcDateTime,
    tuple_in_condition,
    with_row_locks,
)
from airflow.utils.state import DagRunState, State, TaskInstanceState
from airflow.utils.timeout import timeout
from airflow.utils.xcom import XCOM_RETURN_KEY
TR = TaskReschedule
_CURRENT_CONTEXT: list[Context] = []
log = logging.getLogger(__name__)
if TYPE_CHECKING:
    from airflow.models.abstractoperator import TaskStateChangeCallback
    from airflow.models.baseoperator import BaseOperator
    from airflow.models.dag import DAG, DagModel
    from airflow.models.dagrun import DagRun
    from airflow.models.dataset import DatasetEvent