### Apache Airflow version

Other Airflow 2 version (please specify below)

### What happened

Greetings!
Recently I’ve faced a problem. It seems that assigning object, which can’t be serialized to JSON, to the dag_run.conf dict cause critical errors with UI.
After executing code example in "How to reproduce": 
Grid representation of the DAG breaks with following result:
<img width="800" alt="Pasted Graphic" src="https://github.com/apache/airflow/assets/79107237/872ccde5-500f-4484-a36c-dce6b7112286">
Browse -> DAG Runs also becomes unavailable.
<img width="800" alt="Pasted Graphic 1" src="https://github.com/apache/airflow/assets/79107237/b4e3df0c-5324-41dd-96f3-032e706ab7a9">
Dag itself continues to work correctly, this affects only UI graph and dagrun/list/
I suggest to use custom dictionary with restriction on setting non json values.

### What you think should happen instead

Raise an error

### How to reproduce

Execute following task. 
Composer 2 version 2.4.2
Airflow version 2.5.3
```
@task 
def test_task(**context):
    context['dag_run'].conf["test"] = np.int64(1234)
```

### Operating System

Ubuntu 20.04.6 LTS

### Versions of Apache Airflow Providers

_No response_

### Deployment

Google Cloud Composer

### Deployment details

_No response_

### Anything else

_No response_

### Are you willing to submit PR?

- [X] 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)

for down_task_id in task.downstream_task_ids:
                down_task = dag.get_task(down_task_id)
                if not down_task.is_teardown or down_task.on_failure_fail_dagrun:
                    
                    return False
            
            
            return not task.is_teardown or task.on_failure_fail_dagrun
        leaf_task_ids = {x.task_id for x in dag.tasks if is_effective_leaf(x)}
        if not leaf_task_ids:
            
            leaf_task_ids = {x.task_id for x in dag.tasks if not x.downstream_list}
        leaf_tis = {ti for ti in tis if ti.task_id in leaf_task_ids if ti.state != TaskInstanceState.REMOVED}
        return leaf_tis
    @provide_session
    def update_state(
        self, session: Session = NEW_SESSION, execute_callbacks: bool = True
    ) -> tuple[list[TI], DagCallbackRequest | None]:
        """
        Determine the overall state of the DagRun based on the state of its TaskInstances.
        :param session: Sqlalchemy ORM Session
        :param execute_callbacks: Should dag callbacks (success/failure, SLA etc.) be invoked
            directly (default: true) or recorded as a pending request in the ``returned_callback`` property
        :return: Tuple containing tis that can be scheduled in the current loop & `returned_callback` that
            needs to be executed
        """
        
        callback: DagCallbackRequest | None = None
        class _UnfinishedStates(NamedTuple):