clean up code

app/forge.config.ts

 import type { ForgeConfig } from '@electron-forge/shared-types'
 import { MakerSquirrel } from '@electron-forge/maker-squirrel'
 import { MakerZIP } from '@electron-forge/maker-zip'
-import { MakerDeb } from '@electron-forge/maker-deb'
-import { MakerRpm } from '@electron-forge/maker-rpm'
 import { PublisherGithub } from '@electron-forge/publisher-github'
 import { AutoUnpackNativesPlugin } from '@electron-forge/plugin-auto-unpack-natives'
 import { WebpackPlugin } from '@electron-forge/plugin-webpack'
 import * as path from 'path'
 import * as fs from 'fs'
-import * as os from 'fs'
 
 import { mainConfig } from './webpack.main.config'
 import { rendererConfig } from './webpack.renderer.config'

app/src/index.ts

 import { spawn, exec } from 'child_process'
-import { app, autoUpdater, dialog, Tray, Menu, nativeTheme, Notification } from 'electron'
+import { app, autoUpdater, dialog, Tray, Menu, nativeTheme } from 'electron'
 import * as path from 'path'
 import * as fs from 'fs'
 
 require('@electron/remote/main').initialize()
 
 let tray: Tray | null = null
-let secondInstance: Boolean = false
 const SingleInstanceLock = app.requestSingleInstanceLock()
 
 const createSystemtray = () => {