replace deprecated use of pageYOffset

[Shrimpstronaut]

Description

The main library uses the pageYOffset property of the window to get the current scroll position. The property has been deprecated and should be replaced with scrollY.

windowatch/src/index.ts

Lines 569 to 586 in ab94e05

	/**
	* Triggered at each window scroll event.
	*
	* @protected
	* @memberof TaikoLibWindowatch
	*/
	protected windowDidScroll = (): void => {
	const scrollY = window.pageYOffset;
	if (this.scrollY === scrollY) {
	// nothing changed, nothing to do
	return;
	}
	this.scrollY = scrollY;
	this.scrollDidChange = true;
	this.requestFrame();
	};

[Shrimpstronaut]

Due to IE11 support, the proposed change will not be merged.