refactor(@angular/ssr): skip rendering root page during route extraction

To prevent rendering the root route while extracting routes, a non-existent path (`/ng-extract-routes`) is intentionally used. This ensures unnecessary rendering during the route extraction process where now only the app component is rendered.

packages/angular/ssr/src/routes/ng-routes.ts

@@ -407,7 +407,9 @@ export async function getRoutesFromAngularRouterConfig(
   const platformRef = platformServer([
     {
       provide: INITIAL_CONFIG,
-      useValue: { document, url: `${protocol}//${host}/` },
+      // The route below is intentionally set to a non-existent path
+      // to avoid rendering the root route during route extraction.
+      useValue: { document, url: `${protocol}//${host}/ng-extract-routes` },
     },
     {
       provide: ɵConsole,