fix: skip KWOK PrometheusRule when CRD is not available (#171)

## Summary

- Add Capabilities.APIVersions check to the KWOK PrometheusRule template
- Prevents Helm from rendering the PrometheusRule on clusters without
the Prometheus Operator CRD installed
- Fixes integration test failures

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: eliranw

deploy/fake-gpu-operator/templates/status-exporter/kwok-prometheusrule.yaml

@@ -1,4 +1,4 @@
-{{- if and .Values.statusExporter.enabled (ne (.Values.statusExporter.kwok.prometheusRule.enabled | toString) "false") -}}
+{{- if and .Values.statusExporter.enabled (ne (.Values.statusExporter.kwok.prometheusRule.enabled | toString) "false") (.Capabilities.APIVersions.Has "monitoring.coreos.com/v1") -}}
 apiVersion: monitoring.coreos.com/v1
 kind: PrometheusRule
 metadata: