[bot] [main] Automated version update (#2060)

Co-authored-by: Prometheus Operator Bot <prom-op-bot@users.noreply.github.com>

jsonnet/kube-prometheus/versions.json

@@ -6,7 +6,7 @@
   "nodeExporter": "1.5.0",
   "prometheus": "2.43.0",
   "prometheusAdapter": "0.10.0",
-  "prometheusOperator": "0.63.0",
+  "prometheusOperator": "0.64.0",
   "kubeRbacProxy": "0.14.0",
   "configmapReload": "0.5.0",
   "pyrra": "0.5.6"