It's not possible to create a Pod, because of the default overhead value (empty map) in v20.0.0

Describe the bug

The default overhead value of Pod spec in version 20.0.0 is empty map which is causing the following error:

    java.lang.RuntimeException: io.kubernetes.client.openapi.ApiException: Message: 
    HTTP response code: 403
    HTTP response body: {"kind":"Status","apiVersion":"((redacted))","metadata":{},"status":"Failure","message":"pods \"foo\" is forbidden: pod rejected: Pod Overhead set without corresponding RuntimeClass defined Overhead","reason":"Forbidden","details":{"name":"foo","kind":"pods"},"code":403}

As a workaround, one can set the overhead explicitly to null:

V1Pod pod = new V1Pod()
                .metadata(new V1ObjectMeta().name("foo"))
                .spec(new V1PodSpec()
                        .overhead(null)  // HERE: setting the overhead value to null, to avoid above error. 
                        .addContainersItem(new V1ContainerBuilder()
                        // omitted 

Client Version
e.g. 20.0.0

Kubernetes Version
any version

Java Version
any version

To Reproduce
Create a simple Pod, without specifying anything for overhead:

V1Pod pod = new V1Pod()
                .metadata(new V1ObjectMeta().name("foo"))
                .spec(new V1PodSpec()
                        .addContainersItem(new V1ContainerBuilder()
                        .withImage("any-image")
                        .withName("foo-image").build()));

coreV1Api.createNamespacedPod("default", pod).execute();

Expected behavior
Pod creation should be successful but it fails due to overhead: {} being present in the request payload.

I think, either the default value of overhead should be null or when serialising the request, the empty values should be omitted.
KubeConfig
N/A

Server (please complete the following information):
Any

Additional context
N/A

V1PodSpec と CoreV1Api.createNamespacedPod で使用されるリクエストパスから始め、例を再現して、未設定の overhead がどのようにシリアライズされるかを調べます。生成された payload と想定されるリクエストを比較し、overhead を指定せずに Pod を作成した場合に空のマップが送信されなくなり、成功することを確認します。