Removes attached file in message, which is being composed in `MessageInput` component. By default, this function is attached to onPress handler for close button in [FileUploadPreview](../../../core-components/channel.mdx#fileuploadpreview).
It takes index of file (to be removed) in [`fileUploads`](../../../contexts/message_input_context.mdx#fileuploads) array as parameter.

| Type |
| - |
| `(index) => void` |