Fix RSC client data test (#14122)

Author: markdalgleish

integration/client-data-test.ts

@@ -967,6 +967,7 @@ test.describe("Client Data", () => {
                   files: {
                     "react-router.config.ts": reactRouterConfig({
                       splitRouteModules,
+                      viteEnvironmentApi: templateName.includes("rsc"),
                     }),
                     "app/root.tsx": js`
                       import { Outlet, Scripts } from "react-router"