Deleting nested LIC w/ with multiple children doesn't remove bullet

[cmditch]

Description Pressing delete w/ the cursor at the beginning of a nested LIC (list item content) which contains multiple child elements doesn't remove the bullet.

Steps

1. Format some of the words in the list item with rich text (bold, italic), or add a link. Anything to create more than just a single text child for a given list item.
2. Place cursor at beginning of list item.
3. Press delete.

https://user-images.githubusercontent.com/15849320/137414203-efc2ff5c-e544-48e5-bc32-3120c8b9e1f9.mov

Sandbox

https://codesandbox.io/s/plate-playground-v1-2mh1c

Expectation

Content is moved to parent list item (or sub-list item above the currently edited list-item) and the bullet is removed.

Environment

• slate: see sandbox
• slate-react: see sandbox
• browser: chrome