ReactDOM.unmountComponentAtNode does not support callback

[Filipoliko]

ima/packages/core/src/page/renderer/ClientPageRenderer.js

Lines 119 to 126 in 646d467

	unmount() {
	if (this._reactiveView) {
	this._ReactDOM.unmountComponentAtNode(this._viewContainer, () => {
	this._dispatcher.fire(Events.UNMOUNTED, { type: Types.UNMOUNT }, true);
	});
	this._reactiveView = null;
	}
	}

The unmount event is never called, since ReactDOM.unmountComponentAtNode does not take second argument (https://reactjs.org/docs/react-dom.html#unmountcomponentatnode, https://github.com/facebook/react/blob/60016c448bb7d19fc989acd05dda5aca2e124381/packages/react-dom/src/client/ReactDOMLegacy.js#L340). Does this cause any bugs, or can we just remove it?