make Platform.exec async

tabby-core/src/api/platform.ts

@@ -145,7 +145,7 @@ export abstract class PlatformService {
         throw new Error('Not implemented')
     }
 
-    exec (app: string, argv: string[]): void {
+    async exec (app: string, argv: string[]): Promise<void> {
         throw new Error('Not implemented')
     }
 

tabby-electron/src/services/platform.service.ts

@@ -80,8 +80,8 @@ export class ElectronPlatformService extends PlatformService {
         return null
     }
 
-    exec (app: string, argv: string[]): void {
-        execFile(app, argv)
+    async exec (app: string, argv: string[]): Promise<void> {
+        await execFile(app, argv)
     }
 
     isShellIntegrationSupported (): boolean {