Cannot use `<use>` (in `<svg>`) any more

[jbg]

As of #1738 being merged, I can't use <use> inside <svg> in html! {} any more. (Maybe other SVG elements are affected too; I haven't tried.) For example, the following:

html!{
  <a class="btn btn-primary" href="https://example.org/">
    <svg class="bi" fill="currentColor">
      <use href="/bootstrap-icons.svg#wrench"/>
    </svg>
    <span>{"Go to example.org"}</span>
  </a>
}

fails with this error:

error: expected a valid html element
   --> src/pages/example.rs:140:19
    |
140 |                   <use href="/bootstrap-icons.svg#wrench"/>
    |                   ^

Originally posted by @jbg in #1738 (comment)

[siku2]

There we go, thanks for the report!