Call repository function in static function.

### Describe the bug

I need user list in static function of controller.
```
export class NotificationController {
constructor(
@repository(UserRepository) public userRepository: UserRepository,
) {
}

public static async sendPushNotification(userId: string) {
const userInfo = await userRepository.findById(userId, {fields: ['pushToken']});
// send push code
}
}
```
But I can not use userRepository and call repository function.
Is there solution for this?

### Logs

_No response_

### Additional information

_No response_

### Reproduction

I write code

Start with the NotificationController example and the injected UserRepository usage shown in the issue. Determine whether static controller methods are expected to receive repository dependencies; done means confirming and documenting a supported way to access UserRepository from sendPushNotification.

Written by the indexing model from the issue text.