docs: convert all @experimental tags to @publicApi tags (#26595)

PR Close #26595

packages/router/src/router_config_loader.ts

@@ -15,7 +15,7 @@ import {flatten, wrapIntoObservable} from './utils/collection';
 
 /**
  * @docsNotRequired
- * @experimental
+ * @publicApi
  */
 export const ROUTES = new InjectionToken<Route[][]>('ROUTES');