fix: fix incorrect return type

src/preload/index.ts

@@ -12,7 +12,7 @@ contextBridge.exposeInMainWorld('mainApi', {
       throw new Error(`Unknown ipc channel name: ${channel}`)
     }
   },
-  sendSync: (channel: string, ...data: any[]): void => {
+  sendSync: (channel: string, ...data: any[]): any => {
     if (mainAvailChannels.includes(channel)) {
       return ipcRenderer.sendSync.apply(null, [channel, ...data])
     }