`animated` modifier not being respected when used with `format_webp`

[jameswragg]

Environment

Node v20.12.1

Reproduction

/format_auto,animated/ should negotiate only the image formats that support animation (webp/gif)

Describe the bug

The following code tries to limit the format_auto modifier to image formats that support animation but animated is always falsy https://github.com/unjs/ipx/blob/main/src/server.ts#L183-L186

Additional context

No response

Logs

No response