### 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.
start_date = TEST_DATE
        delta = timedelta(days=1)
        dag = models.DAG("dummy-dag", schedule=delta)
        dag_dates = dag.date_range(start_date=start_date, num=3)
        assert dag_dates == [
            start_date,
            start_date + delta,
            start_date + 2 * delta,
        ]
    def test_dag_owner_links(self):
        dag = DAG(
            "dag",
            start_date=DEFAULT_DATE,
            owner_links={"owner1": "https://mylink.com", "owner2": "mailto:someone@yoursite.com"},
        )
        assert dag.owner_links == {"owner1": "https://mylink.com", "owner2": "mailto:someone@yoursite.com"}
        session = settings.Session()
        dag.sync_to_db(session=session)
        expected_owners = {"dag": {"owner1": "https://mylink.com", "owner2": "mailto:someone@yoursite.com"}}
        orm_dag_owners = DagOwnerAttributes.get_all(session)