`HtmlElement::scroll_top` has incorrect return type

[bicarlsen]

Describe the Bug

HtmlElement::scroll_top should return an f64 but returns an i32. This seems to cause jank when relying on this value to set a buffer in list and table virtualization.

Steps to Reproduce

Call HtmlElement::scroll_top.

Expected Behavior

Should return an f64.

Actual Behavior

Returns an i32.