Superfluous text node in `root` when using react

[robin-drexler]

It appears that when using react, the root always contains a text node, even though you didn't render one

to reproduce:

checkout the rd/text-node branch and run pnpm run example:kitchen-sink, open the browser and select react.

You'll see that in addition to the ui-stack, root.children also has an empty text node.

[robin-drexler]

Just noticed that this doesn't occur when you select the iframe as remote env, only in the web worker