Automatic update from web-platform-tests script: Do not clone nodes into a live document for SVG's `<use>` Cloning nodes into a live document fires their connection steps, which can do things like load `<iframe>` contents. This is not good. Instead of doing this, clone the entire SVG tree into a `DocumentFragment` so that all nodes are essentially inert. This prevents infinite recursion when combining `<use>` with `<iframe>` as `<iframe>` attachment steps trigger synchronous layouts, which in turn trigger SVG cloning and rasterization again. Signed-off-by: Martin Robinson <mrobinson@igalia.com> Co-authored-by: Oriol Brufau <obrufau@igalia.com> -- wpt-commits: 88152b842c3f60c2a5f95e0106ded4a375f710b0 wpt-pr: 61074