examples: cleanup thanos-sidecar addon imports

Signed-off-by: Damien Grisonnet <dgrisonn@redhat.com>

example.jsonnet

@@ -5,7 +5,6 @@ local kp =
   // (import 'kube-prometheus/addons/managed-cluster.libsonnet') +
   // (import 'kube-prometheus/addons/node-ports.libsonnet') +
   // (import 'kube-prometheus/addons/static-etcd.libsonnet') +
-  // (import 'kube-prometheus/addons/thanos-sidecar.libsonnet') +
   // (import 'kube-prometheus/addons/custom-metrics.libsonnet') +
   // (import 'kube-prometheus/addons/external-metrics.libsonnet') +
   {