refactor: update preloader d.ts

[unliar]

Description

Using typeof to resolve manual type definition.

// preloader index.ts
export type api = typeof api 

// preloader index.d.ts
import { ElectronAPI } from '@electron-toolkit/preload'
import type { api } from './index'
declare global {
  interface Window {
    electron: ElectronAPI
    api: api
  }
}

Additional context

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).