@hookimpl on_dag_run_running, on_dag_run_success, on_dag_run_failed do not find Connections and Variables

### Apache Airflow version

Other Airflow 2 version (please specify below)

### If "Other Airflow 2 version" selected, which one?

2.8.1

### What happened?

I wrote a listener plugin and added it to the plugins directory. The listener includes the methods:
- on_task_instance_running
- on_task_instance_success
- on_task_instance_failed
- on_dag_run_running
- on_dag_run_success
- on_dag_run_failed.
When trying to extract values from Variables and Connections in the on_dag_run_running, on_dag_run_success, on_dag_run_failed methods, an error occurs already when running dag run:
```
Traceback (most recent call last):

File "/home/airflow/.local/lib/python3.9/site-packages/airflow/cli/commands/scheduler_command.py", line 52, in _run_scheduler_job

run_job(job=job_runner.job, execute_callable=job_runner._execute)

File "/home/airflow/.local/lib/python3.9/site-packages/airflow/utils/session.py", line 79, in wrapper

return func(*args, session=session, **kwargs)

File "/home/airflow/.local/lib/python3.9/site-packages/airflow/jobs/job.py", line 393, in run_job

return execute_job(job, execute_callable=execute_callable)

File "/home/airflow/.local/lib/python3.9/site-packages/airflow/jobs/job.py", line 422, in execute_job

ret = execute_callable()

File "/home/airflow/.local/lib/python3.9/site-packages/airflow/jobs/scheduler_job_runner.py", line 855, in _execute

self._run_scheduler_loop()

File "/home/airflow/.local/lib/python3.9/site-packages/airflow/jobs/scheduler_job_runner.py", line 987, in _run_scheduler_loop

num_queued_tis = self._do_scheduling(session)

File "/home/airflow/.local/lib/python3.9/site-packages/airflow/jobs/scheduler_job_runner.py", line 1063, in _do_scheduling

self._start_queued_dagruns(session)

File "/home/airflow/.local/lib/python3.9/site-packages/airflow/jobs/scheduler_job_runner.py", line 1404, in _start_queued_dagruns

dag_run.notify_dagrun_state_changed()

File "/home/airflow/.local/lib/python3.9/site-packages/airflow/models/dagrun.py", line 862, in notify_dagrun_state_changed

get_listener_manager().hook.on_dag_run_running(dag_run=self, msg=msg)

File "/home/airflow/.local/lib/python3.9/site-packages/pluggy/_hooks.py", line 493, in __call__

return self._hookexec(self.name, self._hookimpls, kwargs, firstresult)

File "/home/airflow/.local/lib/python3.9/site-packages/pluggy/_manager.py", line 115, in _hookexec

return self._inner_hookexec(hook_name, methods, kwargs, firstresult)

File "/home/airflow/.local/lib/python3.9/site-packages/pluggy/_callers.py", line 113, in _multicall

raise exception.with_traceback(exception.__traceback__)

File "/home/airflow/.local/lib/python3.9/site-packages/pluggy/_callers.py", line 77, in _multicall

res = hook_impl.function(*args)

File "/opt/airflow/plugins/metadata/airflow_metadata.py", line 206, in on_dag_run_running

my_connection = BaseHook.get_connection("my_connection")

File "/home/airflow/.local/lib/python3.9/site-packages/airflow/hooks/base.py", line 82, in get_connection

conn = Connection.get_connection_from_secrets(conn_id)

File "/home/airflow/.local/lib/python3.9/site-packages/airflow/models/connection.py", line 479, in get_connection_from_secrets

raise AirflowNotFoundException(f"The conn_id `{conn_id}` isn't defined")

airflow.exceptions.AirflowNotFoundException: The conn_id `my_connection` isn't defined
```

Although the connection is explicitly defined in Connections and everything works in the case of listening to tasks.

How can I fix it so that if I listen to Dog Run, everything works too?

### What you think should happen instead?

I expect the values to be pulled up from Connection and Variable when listening to DagRun.

### How to reproduce

Add to Connection "my_connection" and add to Variable "environment"

```
from airflow.listeners import hookimpl
from airflow.models.taskinstance import TaskInstance
from airflow.hooks.base import BaseHook
from airflow.models import Variable
from airflow.models.dagrun import DagRun
from airflow.plugins_manager import AirflowPlugin

class AirflowListener:
@hookimpl
def on_task_instance_running(self, task_instance: TaskInstance) -> None:
my_connection = BaseHook.get_connection("my_connection")
env = Variable.get("environment")

@hookimpl
def on_task_instance_success(self, task_instance: TaskInstance) -> None:
my_connection = BaseHook.get_connection("my_connection")
env = Variable.get("environment")

@hookimpl
def on_task_instance_failed(self, task_instance: TaskInstance) -> None:
my_connection = BaseHook.get_connection("my_connection")
env = Variable.get("environment")

@hookimpl
def on_dag_run_running(self, dag_run: DagRun):
my_connection = BaseHook.get_connection("my_connection")
env = Variable.get("environment")

@hookimpl
def on_dag_run_success(self, dag_run: DagRun):
my_connection = BaseHook.get_connection("my_connection")
env = Variable.get("environment")

@hookimpl
def on_dag_run_failed(self, dag_run: DagRun):
my_connection = BaseHook.get_connection("my_connection")
env = Variable.get("environment")


class AirflowListenerPlugin(AirflowPlugin):
name = "AirflowListener"
listeners = [AirflowListener()]

```

### Operating System

macOS Sonoma 14.1.2

### Versions of Apache Airflow Providers

_No response_

### Deployment

Docker-Compose

### Deployment details

apache/airflow:2.8.1-python3.9
executor: CeleryExecutor

### 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)

Start by tracing the DAG-run listener call from airflow/models/dagrun.py, notify_dagrun_state_changed, through airflow/hooks/base.py and the connection lookup shown in the traceback. Compare that path with the task-instance listener path in the reproduction. Done means the three DAG-run hooks can retrieve the configured connection and variable, with coverage for the reported failure.

Written by the indexing model from the issue text.