failed to close WebSocket: received header with unexpected rsv bits set: true:true:true

What is the error type of this error so I can ignore it?

Here is an example of an error type within this library.

```go
closeErr := new(websocket.CloseError)
if errors.As(err, closeErr) {
...
}
```

`websocket.CloseError` is an error type within this library.

So, what error type is returned when you receive the error `failed to close WebSocket: received header with unexpected rsv bits set: true:true:true`?

从报告的关闭错误和 websocket.CloseError 示例开始，然后追踪库对 WebSocket 关闭错误的处理，以确定返回的错误类型。确认该类型是否适合使用 errors.As 进行匹配，并记录结果，以便用户能够可靠地忽略此条件。

由索引模型根据 Issue 内容生成。