When is ESM support planned?

### Pre-flight checklist

- [X] I have read the [contribution documentation](https://github.com/electron/forge/blob/main/CONTRIBUTING.md) for this project.
- [X] I agree to follow the [code of conduct](https://github.com/electron/electron/blob/main/CODE_OF_CONDUCT.md) that this project uses.
- [X] I have searched the issue tracker for a feature request that matches the one I want to file, without success.

### Problem description

When I wanted to migrate to ESM according to the latest version of electron-store, I found that forge.config.ts did not support ESM.

### Proposed solution

Support ESM in forge.config

### Alternatives considered

1. Wait for official support in future electron-forge versions.
2. Use a custom build process outside of electron-forge to support ESM.
3. Revert to CommonJS modules for the time being

### Additional information

ESM support is crucial for our project as we aim to use modern JavaScript features and improve code maintainability. The ability to use 'import' statements directly would significantly simplify our development process and allow us to better align with current JavaScript best practices. We've already migrated most of our codebase to use ESM syntax, and electron-forge's lack of support is the main blocker for our complete transition