### 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)

"""Shows configuration."""
        raw = request.args.get("raw") == "true"
        title = "Airflow Configuration"
        expose_config = conf.get("webserver", "expose_config").lower()
        
        if raw:
            if expose_config == "non-sensitive-only":
                updater = configupdater.ConfigUpdater()
                updater.read(AIRFLOW_CONFIG)
                for sect, key in conf.sensitive_config_values:
                    if updater.has_option(sect, key):
                        updater[sect][key].value = "< hidden >"
                config = str(updater)
            elif expose_config in {"true", "t", "1"}:
                with open(AIRFLOW_CONFIG) as file:
                    config = file.read()
            else:
                config = (
                    "# Your Airflow administrator chose not to expose the configuration, "
                    "most likely for security reasons."
                )
            return Response(
                response=config,
                status=200,
                mimetype="application/text",
                headers={"Deprecation": "Endpoint will be removed in Airflow 3.0, use the REST API instead."},
            )
        if expose_config in {"non-sensitive-only", "true", "t", "1"}:
            display_sensitive = expose_config != "non-sensitive-only"