GenericClient shouldn't dispose underlying client

[IvanJosipovic]

Describe the bug
When the GenericClient is disposed, it also disposes the underlying Kubernetes client.

I think we should disable this functionality or make it opt in as the GenericClient is resource specific.

csharp/src/KubernetesClient/GenericClient.cs

Line 154 in 729b10c

kubernetes.Dispose();