bug: fresh islands are broken with preact 1.22.1

[JOTSR]

Fresh island rendering is broken in preact 1.22.1

Bug

children.js:123 Uncaught (in promise) TypeError: n2.contains is not a function
    at S (children.js:123:16)
    at O (index.js:246:4)
    at S (children.js:85:3)
    at O (index.js:246:4)
    at B (render.js:37:2)
    at _render (main.ts:109:7)

It seems that fresh root fragments of islands are missing contains method.

Bug reason

The PR replace isConnected with parentDom.contains #4421 breaks fresh island rendering with new contains method.

[marvinhagemeister]

Resolved in #2596