### 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)

if conf.has_option("email", key):
                    path = conf.get_mandatory_value("email", key)
                    try:
                        with open(path) as f:
                            content = f.read()
                    except FileNotFoundError:
                        self.log.warning(f"Could not find email template file '{path!r}'. Using defaults...")
                    except OSError:
                        self.log.exception(f"Error while using email template '{path!r}'. Using defaults...")
                return render_template_to_string(jinja_env.from_string(content), jinja_context)
            subject = render("subject_template", default_subject)
            html_content = render("html_content_template", default_html_content)
            html_content_err = render("html_content_template", default_html_content_err)
        return subject, html_content, html_content_err
    def email_alert(self, exception, task: BaseOperator) -> None:
        """Send alert email with exception information."""
        subject, html_content, html_content_err = self.get_email_subject_content(exception, task=task)
        assert task.email
        try:
            send_email(task.email, subject, html_content)
        except Exception:
            send_email(task.email, subject, html_content_err)
    def set_duration(self) -> None:
        """Set TI duration"""
        if self.end_date and self.start_date:
            self.duration = (self.end_date - self.start_date).total_seconds()
        else:
            self.duration = None
        self.log.debug("Task Duration set to %s", self.duration)
    def _record_task_map_for_downstreams(self, task: Operator, value: Any, *, session: Session) -> None: