chore(deps): update quay.io/brancz/kube-rbac-proxy docker tag to v0.20.0 (#409)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

chart/growthbook-controller/values.yaml

@@ -126,7 +126,7 @@ prometheusRule:
 
 kubeRBACProxy:
   enabled: true
-  image: quay.io/brancz/kube-rbac-proxy:v0.19.1
+  image: quay.io/brancz/kube-rbac-proxy:v0.20.0
   securityContext:
     allowPrivilegeEscalation: false
     capabilities: