### Apache Airflow version

2.7.0rc1

### What happened

As per https://github.com/apache/airflow/pull/31583, now we can only run DAG with config from UI if DAG has params, however, if a DAG is using dag_run.conf there is no way to run with config from UI and as dag_run.conf is not deprecated most of the users will be impacted by this

@hussein-awala  also mentioned it in his [voting](https://lists.apache.org/thread/zd9ppxw1xwxsl66w0tyw1wch9flzb03w)

### What you think should happen instead

I think there should be a way to provide param values from UI when dag_run.conf is used in DAG

### How to reproduce

Use below DAG in 2.7.0rc and you will notice there is no way to provide conf value from airflow UI

DAG CODE

```
from airflow.models import DAG
from airflow.operators.bash import BashOperator
from airflow.operators.python import PythonOperator
from airflow.utils.dates import days_ago

dag = DAG(
dag_id="trigger_target_dag",
default_args={"start_date": days_ago(2), "owner": "Airflow"},
tags=["core"],
schedule_interval=None, # This must be none so it's triggered by the controller
is_paused_upon_creation=False, # This must be set so other workers can pick this dag up. mabye it's a bug idk
)

def run_this_func(**context):
print(
f"Remotely received value of {context['dag_run'].conf['message']} for key=message "
)

run_this = PythonOperator(
task_id="run_this",
python_callable=run_this_func,
dag=dag,
)

bash_task = BashOperator(
task_id="bash_task",
bash_command='echo "Here is the message: $message"',
env={"message": '{{ dag_run.conf["message"] if dag_run else "" }}'},
dag=dag,
)
```

### Operating System

MAS os Monterey

### Versions of Apache Airflow Providers

_No response_

### Deployment

Astronomer

### Deployment details

_No response_

### Anything else

_No response_

### 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)

query_date = base_date
    if date_time < base_date <= date_time + datetime.timedelta(seconds=1):
        query_date = date_time
    drs = session.scalars(
        select(DagRun)
        .where(DagRun.dag_id == dag.dag_id, DagRun.execution_date <= query_date)
        .order_by(desc(DagRun.execution_date))
        .limit(num_runs)
    ).all()
    dr_choices = []
    dr_state = None
    for dr in drs:
        dr_choices.append((dr.execution_date.isoformat(), dr.run_id))
        if date_time == dr.execution_date:
            dr_state = dr.state
    
    if not dr_state and drs:
        dr = drs[0]
        date_time = dr.execution_date
        dr_state = dr.state
    return {
        "dttm": date_time,
        "base_date": base_date,
        "num_runs": num_runs,
        "execution_date": date_time.isoformat(),
        "dr_choices": dr_choices,
        "dr_state": dr_state,
    }
def _safe_parse_datetime(v, allow_empty=False) -> datetime.datetime | None: