Safari 16.4 does no longer reflect zoom factor to `currentScale`

[yhatt]

WebKit/WebKit@0f17225

marpit-svg-polyfill/src/polyfill.ts

Lines 82 to 85 in f5a1c6e

	// NOTE: Safari reflects a zoom level to SVG's currentScale property, but
	// the other browsers will always return 1. You have to specify the zoom
	// factor manually if used in outdated Blink engine. (e.g. Electron)
	const zoomFactor = zoom || zoomFactorFromParent || svg.currentScale || 1