Cannot override sendEmailConfirmation controller - users-permissions plugin (Strapi v5)
### Node Version

22.4.0

### NPM/Yarn/PNPM Version

Yarn 4.6.0

### Strapi Version

5.8.1

### Operating System

MacOS

### Database

MySQL

### Javascript or Typescript

Typescript

### Reproduction URL

_No response_

### Bug Description

### Context

When a user registers, I am trying to add an expiry to the token in the link sent to their email.  
**Assumption:** `sendEmailConfirmation` controller is what should be handling that.

I have to override other auth controllers in the `users-permissions` plugin, and those work fine.  

However, when trying to override the `sendEmailConfirmation` controller in exactly the same way, it never fires, and therefore I cannot override anything.

I have seen similar issues around but none of them fit this one / it is not a duplicate that I am aware of.

### Steps to Reproduce

1. Run the code below.
2. Register a new user
3. Observe no logs from `sendEmailConfirmation`

### Expected Behavior

Expected `sendEmailConfirmation` to fire.

### Logs

```shell

```

### Code Snippets

### `index.ts`

```typescript
    import type { Core } from "@strapi/strapi";
    import { registerAuthControllers } from "./utils/register-utils/custom-auth-controllers";
  
    export default {
      register({ strapi }: { strapi: Core.Strapi }) {
        registerAuthControllers(strapi);
      },
    
      async bootstrap({ strapi }: { strapi: Core.Strapi }) {
      },
    };
````

---

### `custom-auth-controllers.ts`

```typescript
import { Core } from "@strapi/strapi";
import authController from "../../extensions/users-permissions/controllers/auth";

export const registerAuthControllers = (strapi: Core.Strapi) => {
  const upPlugin = strapi.plugin("users-permissions");

  if (upPlugin && upPlugin.controllers && upPlugin.controllers.auth) {
    upPlugin.controllers.auth.forgotPassword = authController.forgotPassword; 
    upPlugin.controllers.auth.resetPassword = authController.resetPassword;
    upPlugin.controllers.auth.callback = authController.callback;
    upPlugin.controllers.auth.sendEmailConfirmation =
      authController.sendEmailConfirmation;
    upPlugin.controllers.auth.emailConfirmation =
      authController.emailConfirmation;
  } else {
    console.error(
      "Error: Unable to locate auth controller for users-permissions plugin.",
    );
  }
};
````

---

### `auth.ts`

```typescript
import jwt from "jsonwebtoken";
import crypto from "crypto";
import { Context } from "koa";

export default {

  async sendEmailConfirmation(ctx: Context) {
    // never fires...
    console.log("sendEmailConfirmation called....");
    console.log("*****************************");
    console.log("*****************************");
    console.log("*****************************");
    console.log("*****************************");
    console.log("*****************************");
    console.log("*****************************");
  },

  async emailConfirmation(ctx: Context) {
     // works fine...
  }

  async callback(ctx: Context) {
    // works fine...
  },

  async forgotPassword(ctx: Context) {
    // works fine...
  },

  async resetPassword(ctx: Context) {
    // works fine...
  },
};
```

### Media

_No response_

### Additional information

_No response_

### Confirmation Checklist

- [x] I have checked the existing [issues](https://github.com/strapi/strapi/issues) for duplicates.
- [x] I agree to follow this project's [Code of Conduct](https://github.com/strapi/strapi/blob/develop/CODE_OF_CONDUCT.md).