fix(CountButton): add Task yield prevent block thread (#7306)

Author: ArgoZhang

src/BootstrapBlazor/Components/Button/CountButton.cs

@@ -1,4 +1,4 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the Apache 2.0 License
 // See the LICENSE file in the project root for more information.
 // Maintainer: Argo Zhang(argo@live.ca) Website: https://www.blazor.zone
@@ -36,6 +36,7 @@ protected override async Task OnClickButton()
         IsAsyncLoading = true;
         IsDisabled = true;
 
+        await Task.Yield();
         await HandlerClick();
         await UpdateCount();