Use In-built support for PodDisruptionBudget in CNPG cluster of Kunai

As we have In-built support for PDB in CNPG https://cloudnative-pg.io/documentation/1.24/kubernetes_upgrade/#pod-disruption-budgets , we can take benefit from it and use it it Kunai.

Discussed and implemented in Harbor CNPG's implementation: !3633 (comment 3336404988)

cc @marc.bailly1 @satyawanj

Edited by Akshay yadav