refactor: 移除不需要的 OnKeyDownAsync 回调

Author: ArgoZhang

src/BootstrapBlazor/Components/Textarea/Textarea.razor.cs

@@ -3,8 +3,6 @@
 // See the LICENSE file in the project root for more information.
 // Maintainer: Argo Zhang([email protected]) Website: https://www.blazor.zone
 
-using Microsoft.AspNetCore.Components.Web;
-
 namespace BootstrapBlazor.Components;
 
 /// <summary>
@@ -36,13 +34,6 @@ public partial class Textarea
     [Parameter]
     public bool IsAutoScroll { get; set; }
 
-    /// <summary>
-    /// 获得/设置 文本框按键回调委托方法 默认为 null
-    /// <para>返回真时阻止按键</para>
-    /// </summary>
-    [Parameter]
-    public Func<KeyboardEventArgs, Task<bool>>? OnKeyDownAsync { get; set; }
-
     /// <summary>
     /// 获得/设置 是否使用 Shift + Enter 代替原回车按键行为 默认为 false
     /// </summary>