### Apache Airflow version

main (development)

### What happened

Here's a dag:

```python3
from airflow import DAG
from airflow.decorators import task
import airflow.configuration as conf
from datetime import datetime

@task
def print_this(this):
    print(this)

with DAG(dag_id="config_ref", schedule=None, start_date=datetime(1970, 1, 1)) as dag:
    namespace = conf.get("kubernetes", "NAMESPACE")
    print_this(namespace)
```

In 2.4.3 it parses without error, but in main (as of 2e7a4bcb550538283f28550208b01515d348fb51) the reference to the "kubernetes" section breaks.  Likely because of this: https://github.com/apache/airflow/pull/26873
```
❯ airflow dags list-import-errors
filepath                              | error
======================================+========================================================================================================
/Users/matt/2022/11/29/dags/config.py | Traceback (most recent call last):
                                      |   File "/Users/matt/src/airflow/airflow/configuration.py", line 595, in get
                                      |     return self._get_option_from_default_config(section, key, **kwargs)
                                      |   File "/Users/matt/src/airflow/airflow/configuration.py", line 605, in _get_option_from_default_config
                                      |     raise AirflowConfigException(f"section/key [{section}/{key}] not found in config")
                                      | airflow.exceptions.AirflowConfigException: section/key  not found in config
                                      |

❯ python dags/config.py
[2022-11-29 21:30:05,300] {configuration.py:603} WARNING - section/key [kubernetes/namespace] not found in config
Traceback (most recent call last):
  File "/Users/matt/2022/11/29/dags/config.py", line 13, in <module>
    namespace = conf.get("kubernetes", "NAMESPACE")
  File "/Users/matt/src/airflow/airflow/configuration.py", line 1465, in get
    return conf.get(*args, **kwargs)
  File "/Users/matt/src/airflow/airflow/configuration.py", line 595, in get
    return self._get_option_from_default_config(section, key, **kwargs)
  File "/Users/matt/src/airflow/airflow/configuration.py", line 605, in _get_option_from_default_config
    raise AirflowConfigException(f"section/key [{section}/{key}] not found in config")
airflow.exceptions.AirflowConfigException: section/key [kubernetes/namespace] not found in config
```

To quote @jedcunningham :
>  The backcompat layer only expects you to use the “new” section name.




### What you think should happen instead

The recent section name change should be registered so that the old name still works.

### How to reproduce

See above

### Operating System

Mac OS / venv

### Versions of Apache Airflow Providers

n/a

### Deployment

Virtualenv installation

### Deployment details

`pip install -e ~/src/airflow` into a fresh venv

### Anything else

Also, it's kind of weird that the important part of the error message (which section?) is missing from `list-import-errors`.  I had to run the dag def like a script to realize that it was the kubernetes section that it was complaining about.


### 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)

self,
        display_source: bool = False,
        display_sensitive: bool = False,
        raw: bool = False,
        include_env: bool = True,
        include_cmds: bool = True,
        include_secret: bool = True,
    ) -> ConfigSourcesType:
        """
        Returns the current configuration as an OrderedDict of OrderedDicts.
        When materializing current configuration Airflow defaults are
        materialized along with user set configs. If any of the `include_*`
        options are False then the result of calling command or secret key
        configs do not override Airflow defaults and instead are passed through.
        In order to then avoid Airflow defaults from overwriting user set
        command or secret key configs we filter out bare sensitive_config_values
        that are set to Airflow defaults when command or secret key configs
        produce different values.
        :param display_source: If False, the option value is returned. If True,
            a tuple of (option_value, source) is returned. Source is either
            'airflow.cfg', 'default', 'env var', or 'cmd'.
        :param display_sensitive: If True, the values of options set by env
            vars and bash commands will be displayed. If False, those options
            are shown as '< hidden >'
        :param raw: Should the values be output as interpolated values, or the
            "raw" form that can be fed back in to ConfigParser
        :param include_env: Should the value of configuration from AIRFLOW__
            environment variables be included or not
        :param include_cmds: Should the result of calling any *_cmd config be
            set (True, default), or should the _cmd options be left as the