### 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=execution_date,
            end_date=execution_date,
            dag_run_state=False,  
            session=session,
        )
        self.log.debug("Getting dagrun for dag %s", self.dag_id)
        dr: DagRun = _get_or_create_dagrun(
            dag=self,
            start_date=execution_date,
            execution_date=execution_date,
            run_id=DagRun.generate_run_id(DagRunType.MANUAL, execution_date),
            session=session,
            conf=run_conf,
        )
        tasks = self.task_dict
        self.log.debug("starting dagrun")
        
        
        
        while dr.state == State.RUNNING:
            schedulable_tis, _ = dr.update_state(session=session)
            for ti in schedulable_tis:
                add_logger_if_needed(ti)
                ti.task = tasks[ti.task_id]
                _run_task(ti, session=session)
        if conn_file_path or variable_file_path:
            
            secrets_backend_list.pop(0)
    @provide_session
    def create_dagrun(