Get rid of this.disposers while registering stuff in extensions (#1148)

Signed-off-by: Roman <ixrock@gmail.com>

extensions/metrics-cluster-feature/renderer.tsx

@@ -1,25 +1,23 @@
-import { Registry, LensRendererExtension } from "@k8slens/extensions"
+import { LensRendererExtension } from "@k8slens/extensions"
 import { MetricsFeature } from "./src/metrics-feature"
 import React from "react"
 
 export default class ClusterMetricsFeatureExtension extends LensRendererExtension {
-  registerClusterFeatures(registry: Registry.ClusterFeatureRegistry) {
-    this.disposers.push(
-      registry.add({
-        title: "Metrics Stack",
-        components: {
-          Description: () => {
-            return (
-              <span>
+  clusterFeatures = [
+    {
+      title: "Metrics Stack",
+      components: {
+        Description: () => {
+          return (
+            <span>
                 Enable timeseries data visualization (Prometheus stack) for your cluster.
                 Install this only if you don't have existing Prometheus stack installed.
                 You can see preview of manifests <a href="https://github.com/lensapp/lens/tree/master/extensions/lens-metrics/resources" target="_blank">here</a>.
               </span>
-            )
-          }
-        },
-        feature: new MetricsFeature()
-      })
-    )
-  }
+          )
+        }
+      },
+      feature: new MetricsFeature()
+    }
+  ]
 }