helm-chart: support modern api-version of PDBs
{{- if .Values.pdb.enabled -}}
+{{- if .Capabilities.APIVersions.Has "policy/v1/PodDisruptionBudget" }}
+apiVersion: policy/v1
+{{- else }}
apiVersion: policy/v1beta1
+{{- end }}
kind: PodDisruptionBudget
metadata:
name: binderhub
