### Apache Airflow version

2.5.1

### What happened

/calendar page give a problem, here is the capture



![屏幕截图 2023-01-30 093116](https://user-images.githubusercontent.com/19165258/215369479-9fc7de5c-f190-460c-9cf7-9ab27d8ac355.png)


### What you think should happen instead

_No response_

### How to reproduce

_No response_

### Operating System

Ubuntu 22.04.1 LTS

### Versions of Apache Airflow Providers

Distributor ID: Ubuntu
Description:    Ubuntu 22.04.1 LTS
Release:        22.04
Codename:       jammy

### Deployment

Other

### Deployment details


Distributor ID: Ubuntu
Description:    Ubuntu 22.04.1 LTS
Release:        22.04
Codename:       jammy

### 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)

url = "code?dag_id=example_bash_operator"
    resp = admin_client.get(url, follow_redirects=True)
    check_content_not_in_response("Failed to load DAG file Code", resp)
    check_content_in_response("example_bash_operator", resp)
def test_code_from_db(admin_client):
    dag = DagBag(include_examples=True).get_dag("example_bash_operator")
    DagCode(dag.fileloc, DagCode._get_code_from_file(dag.fileloc)).sync_to_db()
    url = "code?dag_id=example_bash_operator"
    resp = admin_client.get(url, follow_redirects=True)
    check_content_not_in_response("Failed to load DAG file Code", resp)
    check_content_in_response("example_bash_operator", resp)
def test_code_from_db_all_example_dags(admin_client):
    dagbag = DagBag(include_examples=True)
    for dag in dagbag.dags.values():
        DagCode(dag.fileloc, DagCode._get_code_from_file(dag.fileloc)).sync_to_db()
    url = "code?dag_id=example_bash_operator"
    resp = admin_client.get(url, follow_redirects=True)
    check_content_not_in_response("Failed to load DAG file Code", resp)
    check_content_in_response("example_bash_operator", resp)
@pytest.mark.parametrize(
    "url, data, content",
    [
        ("paused?dag_id=example_bash_operator&is_paused=false", None, "OK"),
        (
            "failed",
            dict(