chore: try stub the module

Author: antfu

packages/devtools/package.json

@@ -32,9 +32,10 @@
     "build": "pnpm dev:prepare && pnpm build:module && pnpm build:client && esno scripts/prepare.ts",
     "build:client": "nuxi generate client",
     "build:module": "nuxt-build-module build",
+    "stub": "nuxt-build-module build --stub",
     "dev": "nuxi dev client",
     "dev:playground": "pnpm build && nuxi dev playground",
-    "dev:prepare": "nuxi prepare client",
+    "dev:prepare": "pnpm run stub && nuxi prepare client",
     "prepack": "pnpm build"
   },
   "peerDependencies": {