build: update prepublish script to use pnpm build

- switch from nr build to pnpm build for consistency with other scripts
- ensures compatibility and streamlines build process

package.json

@@ -31,7 +31,7 @@
     "build": "unbuild",
     "dev": "unbuild --stub",
     "lint": "pnpm dev && eslint .",
-    "prepublishOnly": "nr build",
+    "prepublishOnly": "pnpm build",
     "release": "bumpp && pnpm publish",
     "start": "esno src/index.ts",
     "test": "vitest",