Force to welcome page when init.js in project folder root (Only in development mode)
<!--
Hello 👋 Thank you for submitting an issue.

Before you start, please make sure your issue is understandable and reproducible.
To make your issue readable make sure you use valid Markdown syntax.

https://guides.github.com/features/mastering-markdown/

Please ensure you have also read and understand the contributing guide.

https://github.com/strapi/strapi/blob/main/CONTRIBUTING.md#reporting-an-issue
-->

## Bug report

### Required System information

- Node.js version: v22.12.0
- NPM version: 9.9.3
- Strapi version: 5.5.1 / 5.5.2
- Database: sqlite
- Operating system:  Windows 11 24H2 WSL (Ubuntu 20.04.6 LTS)
- Is your project Javascript or Typescript: Both

### Describe the bug

_Only in development mode_

If there is a file name `init.js` in the project folder root. No one can enter to the login page.

### Steps to reproduce the behavior

1. `npx create-strapi-app@latest`  with all default settings.
2. cd to the project folder
3. `touch init.js`  <= important step
4. `npm run develop` 
5. In open welcome page on your browser, register a super admin.
6. open a new browser session to http://localhost:1337/admin
7. not show the login page, instead of show the `/admin/auth/register-admin` page
8. register again got `You cannot register a new super admin` message (since the super admin was created on step 5.)

### Expected behavior

User (Developer) can enter login page even when `init.js` exist.

### Screenshots

N/A

### Code snippets

N/A

### Additional context

The `init.js` content will be output as `http://localhost:1337/admin/init` content.






