Plugin.json: update with extensions info (#4407)

### What changed?

- Manually added ui-extensions metadata to the plugin.json (to be able
to lazy-load plugins in Grafana, based on [this
PR](grafana/grafana#88288)

grafana-plugin/src/plugin.json

@@ -592,5 +592,13 @@
   "dependencies": {
     "grafanaDependency": ">=9.2.0",
     "plugins": []
-  }
+  },
+  "extensions": [
+    {
+      "extensionPointId": "grafana/user/profile/tab",
+      "title": "IRM",
+      "description": "IRM settings",
+      "type": "component"
+    }
+  ]
 }