bump kube-prometheus-stack to 23.2.0

this release contains the prometheus operator in version 0.52.1

see https://github.com/fluxcd/flux2/issues/2192
https://github.com/fluxcd/flux2/pull/2193

 for issues

Signed-off-by: Johannes Graf <graf@synyx.de>

manifests/monitoring/kube-prometheus-stack/release.yaml

@@ -6,7 +6,7 @@ spec:
   interval: 5m
   chart:
     spec:
-      version: 19.3.0
+      version: 23.2.0
       chart: kube-prometheus-stack
       sourceRef:
         kind: HelmRepository