### Apache Airflow version

2.5.0

### What happened

Specifying a `note`  in the payload (as mentioned [in the doc](https://airflow.apache.org/docs/apache-airflow/2.5.0/stable-rest-api-ref.html#operation/post_dag_run)) when triggering a new dag run yield a 400 bad request


(Git Version: .release:2.5.0+fa2bec042995004f45b914dd1d66b466ccced410)




### What you think should happen instead

As far as I understand the documentation, I should be able to set a note for this dag run, and it is not the case.

### How to reproduce


This is a local airflow, using default credentials and default setup when following [this guide](https://airflow.apache.org/docs/apache-airflow/stable/howto/docker-compose/index.html#)

DAG: 

<details>

```
import airflow
from airflow import DAG

import logging

from airflow.operators.python import PythonOperator
from airflow.operators.dummy import DummyOperator

from datetime import timedelta

logger = logging.getLogger("airflow.task")

default_args = {
    "owner": "airflow",
    "depends_on_past": False,
    "retries": 0,
    "retry_delay": timedelta(minutes=5),
}

def log_body(**context):
    logger.info(f"Body: {context['dag_run'].conf}")


with DAG(
        "my-validator",
        default_args=default_args,
        schedule_interval=None,
        start_date=airflow.utils.dates.days_ago(0),
        catchup=False
) as dag:
    (
        PythonOperator(
            task_id="abcde",
            python_callable=log_body,
            provide_context=True
        )
        >> DummyOperator(
            task_id="todo"
        )
    )
```

</details>


Request:

<details>

```
curl --location --request POST '0.0.0.0:8080/api/v1/dags/my-validator/dagRuns' \
--header 'Authorization: Basic YWlyZmxvdzphaXJmbG93' \
--header 'Content-Type: application/json' \
--data-raw '{
  "conf": {
      "key":"value"
  },
  "note": "test"
  }' 
```

</details>

Response: 

<details>

```
{
    "detail": "{'note': ['Unknown field.']}",
    "status": 400,
    "title": "Bad Request",
    "type": "https://airflow.apache.org/docs/apache-airflow/2.5.0/stable-rest-api-ref.html#section/Errors/BadRequest"
}
```

</details>



Removing the `note` key, returns 200... with a null `note`!

<details>

```
{
    "conf": {
        "key": "value"
    },
    "dag_id": "my-validator",
    "dag_run_id": "manual__2023-01-10T10:45:26.102802+00:00",
    "data_interval_end": "2023-01-10T10:45:26.102802+00:00",
    "data_interval_start": "2023-01-10T10:45:26.102802+00:00",
    "end_date": null,
    "execution_date": "2023-01-10T10:45:26.102802+00:00",
    "external_trigger": true,
    "last_scheduling_decision": null,
    "logical_date": "2023-01-10T10:45:26.102802+00:00",
    "note": null,
    "run_type": "manual",
    "start_date": null,
    "state": "queued"
}
```


</details>

### Operating System

Ubuntu 20.04.5 LTS

### Versions of Apache Airflow Providers

_No response_

### Deployment

Docker-Compose

### Deployment details

_No response_

### Anything else

Everytime.

### Are you willing to submit PR?

- [ ] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

"url, request_json, expected_response",
        [
            pytest.param(
                "api/v1/dags/TEST_DAG_ID/dagRuns",
                {
                    "start_date": "2020-06-11T18:00:00+00:00",
                    "execution_date": "2020-06-12T18:00:00+00:00",
                },
                {
                    "detail": "Property is read-only - 'start_date'",
                    "status": 400,
                    "title": "Bad Request",
                    "type": EXCEPTIONS_LINK_MAP[400],
                },
                id="start_date in request json",
            ),
            pytest.param(
                "api/v1/dags/TEST_DAG_ID/dagRuns",
                {"state": "failed", "execution_date": "2020-06-12T18:00:00+00:00"},
                {
                    "detail": "Property is read-only - 'state'",
                    "status": 400,
                    "title": "Bad Request",
                    "type": EXCEPTIONS_LINK_MAP[400],
                },
                id="state in request json",
            ),
        ],
    )
    def test_response_400(self, url, request_json, expected_response):