Guided Tours: Unsafe usage of onTargetDisappear

[sirreal]

This error is sometimes triggered by guided tours:

Uncaught TypeError: e.props.onTargetDisappear is not a function

From #26468 (review)

Observed while testing the mentioned PR, but I had observed this behavior before while implementing #25474

The case mentioned was observed while following the steps of the site icon tour, available at https://wordpress.com/checklist/SIMPLE_SITE_SLUG

The offending call appears to be here:

wp-calypso/client/layout/guided-tours/config-elements/step.js

Lines 183 to 186 in 8d10cb1

	this.props.onTargetDisappear( {
	quit: () => this.context.quit( this.context ),
	next: () => this.skipToNext( this.props, this.context ),
	} );

And the offending tour Step is likely here or nearby:

wp-calypso/client/layout/guided-tours/tours/checklist-site-icon-tour.js

Lines 109 to 126 in 8d10cb1

	<Step
	name="click-done"
	target="image-editor-button-done"
	arrow="bottom-center"
	placement="above"
	style={ { marginTop: '30px', marginLeft: '90px' } }
	>
	{ ( { translate } ) => (
	<Fragment>
	<Continue target="image-editor-button-done" step="finish" click>
	{ translate(
	'Let’s make sure it looks right before you press {{doneButton/}} to save your changes.',
	{ components: { doneButton: <DoneButton /> } }
	) }
	</Continue>
	</Fragment>
	) }
	</Step>