Fix Warning: To load an ES module, set "type": "module"

This happens with Node.js v22.3.0 and Bun v1.1.15

```sh
$ remix vite:dev
  ➜  Local:   http://localhost:5173/
  ➜  Network: use --host to expose
  ➜  press h + enter to show help
(node:71396) Warning: To load an ES module, set "type": "module" in the package.json or use the .mjs extension.
(Use `node --trace-warnings ...` to show where the warning was created)
```