### 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.
"""Stringified DAGs and operators contain exactly these fields."""
        if not cls.__serialized_fields:
            exclusion_list = {
                "parent_dag",
                "schedule_dataset_references",
                "task_outlet_dataset_references",
                "_old_context_manager_dags",
                "safe_dag_id",
                "last_loaded",
                "user_defined_filters",
                "user_defined_macros",
                "partial",
                "params",
                "_pickle_id",
                "_log",
                "task_dict",
                "template_searchpath",
                "sla_miss_callback",
                "on_success_callback",
                "on_failure_callback",
                "template_undefined",
                "jinja_environment_kwargs",
                
                "has_on_success_callback",
                "has_on_failure_callback",
                "auto_register",
            }
            cls.__serialized_fields = frozenset(vars(DAG(dag_id="test")).keys()) - exclusion_list
        return cls.__serialized_fields
    def get_edge_info(self, upstream_task_id: str, downstream_task_id: str) -> EdgeInfoType: