Fix untyped asset loads after #14808. (#15399)

The logic in PR #14808 broke `bevy_asset_loader`, because calling
`AssetServer::load_untyped()` initiates a load of an asset of type
`LoadedUntypedAsset`, which doesn't match any asset loaders and
therefore fails. I reverted the lines that were causing the problem. The
resulting code seems to work, but I'm not sure if this was the correct
fix.

crates/bevy_asset/src/server/mod.rs

@@ -429,12 +429,11 @@ impl AssetServer {
  return handle;
  }
  let id = handle.id().untyped();
- let owned_handle = Some(handle.clone().untyped());
 
  let server = self.clone();
  let task = IoTaskPool::get().spawn(async move {
  let path_clone = path.clone();
- match server.load_internal(owned_handle, path, false, None).await {
+ match server.load_untyped_async(path).await {
  Ok(handle) => server.send_asset_event(InternalAssetEvent::Loaded {
  id,
  loaded_asset: LoadedAsset::new_with_dependencies(