Missing attribute of `file` in InputHTMLAttributes

[keyakko]

A type error occurs when using an Input element with the attribute type="file".

I wrote tsx codes like below.

When I retrieve a file, it cannot be retrieved properly due to a type error.

In this case, event.target will contain HTMLInputElement.
And HTMLInputElement.files is expected to be undefined(optional) or FileList.
https://html.spec.whatwg.org/multipage/input.html#htmlinputelement

attribute FileList? files;

[wonderful-panda]

Try 3.2.0-beta.1