Deprecated: Define .hover() using non-deprecated methods

Make the deprecated `.hover()` method not rely on other deprecated
methods: `.mouseenter()` & `.mouseleave()`. Use `.on()` instead.

Closes gh-5251

(cherry picked from commit fd6ffc5)

src/deprecated/event.js

@@ -28,7 +28,9 @@ jQuery.fn.extend( {
 	},
 
 	hover: function( fnOver, fnOut ) {
-		return this.mouseenter( fnOver ).mouseleave( fnOut || fnOver );
+		return this
+			.on( "mouseenter", fnOver )
+			.on( "mouseleave", fnOut || fnOver );
 	}
 } );