next.js

472c4c02 - Route modules: Call setReferenceManifestsSingleton for app-route to match app-page (#82908)

Route modules: Call setReferenceManifestsSingleton for app-route to match app-page (#82908) ## What? The changes in #82903 highlighted some failing tests because `use cache` relies on the global singleton being set which accidentally depended on the `load-components` call to `setReferenceManifestsSingleton`. The `app-page` template did the right thing calling `setReferenceManifestsSingleton` already but `app-route` did not, causing those tests to fail when I removed calling `setReferenceManifestsSingleton` in the PR further in the stack.