Disable proxyStandardRoutes in classic-remix example

The classic-remix example uses @shopify/remix-oxygen's createRequestHandler
which now defaults to proxyStandardRoutes: true. This requires a storefront
instance with specific methods that the classic-remix example doesn't provide.

Setting proxyStandardRoutes: false restores the previous behavior and fixes
the dev test.

Author: kdaviduik

examples/classic-remix/server.ts

@@ -32,6 +32,7 @@ export default {
         build: remixBuild,
         mode: process.env.NODE_ENV,
         getLoadContext: () => appLoadContext,
+        proxyStandardRoutes: false,
       });
 
       const response = await handleRequest(request);