chore(example-next-js): improve deployment (#1396)

Author: NathanFlurry

examples/next-js/src/app/api/rivet/[...all]/route.ts

@@ -1,4 +1,6 @@
 import { toNextHandler } from "@rivetkit/next-js";
 import { registry } from "@/rivet/registry";
 
+export const maxDuration = 60;
+
 export const { GET, POST, PUT, PATCH, HEAD, OPTIONS } = toNextHandler(registry);

examples/next-js/vercel.json

@@ -0,0 +1,3 @@
+{
+  "fluid": false
+}