fix(vercel): disable framework detection for Remix 1.x

Vercel's Remix builder only supports v2+. Override framework
detection with custom build command for Remix 1.2.2 compatibility.

Author: zainfathoni

vercel.json

@@ -1,4 +1,6 @@
 {
+  "buildCommand": "npm run build",
+  "framework": null,
   "build": {
     "env": {
       "ENABLE_FILE_SYSTEM_API": "1"