Reduce cluster admin permissions for Helm chart

Fix #113 (closed).

#370 (closed) is not resolved yet because Strimzi requires a ClusterRole. See https://github.com/strimzi/strimzi-kafka-operator/discussions/6289.

helm/templates/prometheus/operator-role-binding.yaml

+{{- if not (index .Values "kube-prometheus-stack" "global" "rbac" "create") -}}
+apiVersion: rbac.authorization.k8s.io/v1
+kind: RoleBinding
+metadata:
+  name: {{ template "theodolite.fullname" . }}-kube-prometheus-operator
+  labels:
+    app: {{ template "theodolite.fullname" . }}-kube-prometheus-operator
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: Role
+  name: {{ template "theodolite.fullname" . }}-kube-prometheus-operator
+subjects:
+- kind: ServiceAccount
+  name: {{ template "theodolite.fullname" . }}-kube-prometheus-operator
+  namespace: {{ .Release.Namespace }}
+{{- end }}