### Body

There are some use cases where users want to trigger new DAG run as soon as one finished. This is a request I've seen several times with some variations (for example like this [Stackoverflow question](https://stackoverflow.com/q/75623153/14624409)) but the basic request is the same.

The workaround users do to get such functionality is place `TriggerDagRunOperator` as last task of their DAG invoking the same DAG:

```
from datetime import datetime

from airflow import DAG
from airflow.operators.empty import EmptyOperator
from airflow.operators.trigger_dagrun import TriggerDagRunOperator

with DAG(
    dag_id="example",
    start_date=datetime(2023, 1, 1,),
    catchup=False,
    schedule=None,
) as dag:
    task = EmptyOperator(task_id="first")
    trigger = TriggerDagRunOperator(
        task_id="trigger",
        trigger_dag_id="example",
    )

    task >> trigger

```

As you can see this works nicely:
![Screenshot 2023-03-03 at 14 20 51](https://user-images.githubusercontent.com/45845474/222718862-dfde8a41-24b6-4991-b318-b7f9784514f6.png)

My suggestion is to add first class support for this use case, so the above example will be changed to:

```

from datetime import datetime

from airflow import DAG
from airflow.operators.empty import EmptyOperator
from airflow.operators.trigger_dagrun import TriggerDagRunOperator

with DAG(
    dag_id="example",
    start_date=datetime(2023, 1, 1,),
    catchup=False,
    schedule="@continues",
) as dag:
    task = EmptyOperator(task_id="first")
```

I guess it won't exactly be `"@continues"` but more likely new [ScheduleArg](https://github.com/apache/airflow/blob/8b8552f5c4111fe0732067d7af06aa5285498a79/airflow/models/dag.py#L127) type but I show it like that just for simplification of the idea.

### Committer

- [X] I acknowledge that I am a maintainer/committer of the Apache Airflow project.
with DAG(
                dag_id or f.__name__,
                description=description,
                schedule_interval=schedule_interval,
                timetable=timetable,
                start_date=start_date,
                end_date=end_date,
                full_filepath=full_filepath,
                template_searchpath=template_searchpath,
                template_undefined=template_undefined,
                user_defined_macros=user_defined_macros,
                user_defined_filters=user_defined_filters,
                default_args=default_args,
                concurrency=concurrency,
                max_active_tasks=max_active_tasks,
                max_active_runs=max_active_runs,
                dagrun_timeout=dagrun_timeout,
                sla_miss_callback=sla_miss_callback,
                default_view=default_view,
                orientation=orientation,
                catchup=catchup,
                on_success_callback=on_success_callback,
                on_failure_callback=on_failure_callback,
                doc_md=doc_md,
                params=params,
                access_control=access_control,
                is_paused_upon_creation=is_paused_upon_creation,
                jinja_environment_kwargs=jinja_environment_kwargs,
                render_template_as_native_obj=render_template_as_native_obj,
                tags=tags,