### 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.
assert op1.dag is dag
        assert op1.owner == "owner1"
        assert op2.dag is dag2
        assert op2.owner == "owner2"
        with dag2:
            op3 = EmptyOperator(task_id="op3")
        assert op3.dag is dag2
        assert op3.owner == "owner2"
        with dag:
            with dag2:
                op4 = EmptyOperator(task_id="op4")
            op5 = EmptyOperator(task_id="op5")
        assert op4.dag is dag2
        assert op5.dag is dag
        assert op4.owner == "owner2"
        assert op5.owner == "owner1"
        with DAG("creating_dag_in_cm", start_date=DEFAULT_DATE) as dag:
            EmptyOperator(task_id="op6")
        assert dag.dag_id == "creating_dag_in_cm"
        assert dag.tasks[0].task_id == "op6"
        with dag:
            with dag:
                op7 = EmptyOperator(task_id="op7")
            op8 = EmptyOperator(task_id="op8")
        op9 = EmptyOperator(task_id="op8")
        op9.dag = dag2
        assert op7.dag == dag
        assert op8.dag == dag
        assert op9.dag == dag2
    def test_dag_topological_sort_include_subdag_tasks(self):