[css-view-transitions-1] Fix typo (#8879)

Author: khushalsagar

css-view-transitions-1/Overview.bs

@@ -758,7 +758,7 @@ urlPrefix: https://wicg.github.io/navigation-api/; type: interface;
 	except the following styles added to the [=global view transition user agent style sheet=]:
 
 	```css
-	:root::view-transition-old(*) {
+	:root::view-transition-new(*) {
 		position: absolute;
 		inset-block-start: 0;
 		inline-size: 100%;