enable execute to run sync and async

vscode/microsoft-kiota/src/commands/CloseDescriptionCommand.ts

@@ -28,5 +28,5 @@ export class CloseDescriptionCommand extends Command {
       this._openApiTreeProvider.closeDescription();
       await updateTreeViewIcons(treeViewId, false);
     }
-}  
+  }
 }

vscode/microsoft-kiota/src/commands/Command.ts

@@ -1,5 +1,5 @@
 export abstract class Command {
-  public abstract toString():string;
+  public abstract toString(): string;
 
-  abstract execute(args: unknown):void;
+  abstract execute(args: unknown): Promise<void> | void;
 }