Add `kube_image_pull_duration_seconds`

[gnuletik]

Hi!

Since Kubernetes v1.30, kubelet exposes a metric named image_pull_duration_seconds:
See kubernetes/kubernetes#121719

However, I don't see this metric exposed in the kubelet integration:
https://docs.datadoghq.com/integrations/kubelet/

Could you add support for this metric?

Thanks!