### Apache Airflow version

2.5.2

### What happened

Not sure if this is a feature not a bug, but I can use KubernetesPodOperator fine without setting a kubernetes_conn_id.
For example:
```
start = KubernetesPodOperator(
        namespace="mynamespace",
        cluster_context="mycontext",
        security_context={ 'runAsUser': 1000 },
        name="hello",
        image="busybox",
        image_pull_secrets=[k8s.V1LocalObjectReference('prodregistry')],
        cmds=["sh", "-cx"],
        arguments=["echo Start"],
        task_id="Start",
        in_cluster=False,
        is_delete_operator_pod=True,
        config_file="/home/airflow/.kube/config",
    )
```

But if I add deferrable=True to this it won't work. It seems to require an explicit kubernetes_conn_id (which we don't configure).

Is not possible to the deferrable version to work as the non deferrable one?

### What you think should happen instead

I hoped that kpo deferrable would work the same as non deferrable.

### How to reproduce

Use KPO with deferrable=True but no kubernetes_conn_id setting

### Operating System

Debian 11

### Versions of Apache Airflow Providers

_No response_

### Deployment

Official Apache Airflow Helm Chart

### 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)

env_from = [k8s.V1EnvFromSource(config_map_ref=k8s.V1ConfigMapEnvSource(name="test-config-map"))]
        k = KubernetesPodOperator(
            task_id="task",
            env_from=env_from,
        )
        pod = k.build_pod_request_obj(create_context(k))
        assert pod.spec.containers[0].env_from == env_from
    def test_envs_from_configmaps_backcompat(self):
        
        k = KubernetesPodOperator(
            task_id="task",
            configmaps=["test-config-map"],
        )
        expected = [k8s.V1EnvFromSource(config_map_ref=k8s.V1ConfigMapEnvSource(name="test-config-map"))]
        pod = k.build_pod_request_obj(create_context(k))
        assert pod.spec.containers[0].env_from == expected
    def test_envs_from_secrets(self):
        secret_ref = "secret_name"
        secrets = [Secret("env", None, secret_ref)]
        k = KubernetesPodOperator(
            secrets=secrets,
            task_id="test",
        )
        pod = k.build_pod_request_obj()
        assert pod.spec.containers[0].env_from == [
            k8s.V1EnvFromSource(secret_ref=k8s.V1SecretEnvSource(name=secret_ref))
        ]
    @pytest.mark.parametrize(("in_cluster",), ([True], [False]))
    @patch(HOOK_CLASS)
    def test_labels(self, hook_mock, in_cluster):