Update controller-prometheusrules.yaml (#8902)

As fixed in pull request #7829 for the ServiceMonitor resource, this is also needed for the PrometheusRule. When
upgrading the ingress-nginx chart in our environment (via Pulumi) from a really old version to the latest (4.2.0) we
noticed it wanted to delete the PrometheusRule resource. This PR should fix that.

charts/ingress-nginx/templates/controller-prometheusrules.yaml

@@ -1,4 +1,4 @@
-{{- if and ( .Values.controller.metrics.enabled ) ( .Values.controller.metrics.prometheusRule.enabled ) ( .Capabilities.APIVersions.Has "monitoring.coreos.com/v1" ) -}}
+{{- if and .Values.controller.metrics.enabled .Values.controller.metrics.prometheusRule.enabled -}}
 apiVersion: monitoring.coreos.com/v1
 kind: PrometheusRule
 metadata: