Vite plugin: support `nodeIntegration: true` in the renderer process.

### 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 using the electron forge vite plugin, configuring vite for `nodeIntegration: true` in the renderer process requires too much of vite-specific knowledge and configuration. Further, even if one makes it work, there is no guarantee that it won't break on future updates of the plugin since it such configuration could interfering with internal assumptions of the plugin.

### Proposed solution

Something like the webpack plugin does for this use case. See https://github.com/electron-forge/electron-forge-docs/blob/f83f6237a6e0018c426a1b7efddc8098eca2c01c/config/plugins/webpack.md?plain=1#L269 .

### Alternatives considered

- fragile "Manual" vite configuration as described above.
- shifting a lot of what would be in the renderer into the preload script (incurs more boilerplate and complexity).

### Additional information

_No response_