Tree component not working properly in shadow DOM

[xdev1]

Describe the bug

When the tree component is used in shadow DOM then the keyboard navigation is not working.

To Reproduce

Please try to use the keyboard navigation in the tree element of this demo and you will see that it is broken:
https://jsbin.com/zewifakuke/2/edit?html,output

Source of this bug

The bug can be found here:

shoelace/src/components/tree/tree.ts

Line 231 in e42beab

const activeItemIndex = items.findIndex(item => document.activeElement === item);

Focused elements in the shadow DOM cannot be accessed by document.activeElement.
Just replace that code line in question with the following and everything will work again:

const activeItemIndex = items.findIndex(item => item.matches(':focus'));

[Edit] Something like this may also work, I guess:

const activeItemIndex = items.findIndex(
  item => item === (this.getRootNode() as unknown as DocumentOrShadowRoot).activeElement
);

[claviska]

Thanks! Fixed in ca64d26.