accessibility/rubygem-atk: Update to 4.2.4

Changes:	https://github.com/ruby-gnome/ruby-gnome/releases
		https://github.com/ruby-gnome/ruby-gnome/blob/main/NEWS.md

accessibility/rubygem-atk/Makefile

 PORTNAME=	atk
-PORTVERSION=	4.2.2
+PORTVERSION=	4.2.4
 CATEGORIES=	accessibility rubygems
 MASTER_SITES=	RG
 

accessibility/rubygem-atk/distinfo

-TIMESTAMP = 1712084576
-SHA256 (rubygem/atk-4.2.2.gem) = fe0a968b5c37e8a1fcb8923626b2c8048dcb14ad127ad58025f909a6b2470b0f
-SIZE (rubygem/atk-4.2.2.gem) = 15872
+TIMESTAMP = 1727315440
+SHA256 (rubygem/atk-4.2.4.gem) = 6476d07d896bac66f50c14e788f9978fe9c4fa3cbe4e2cb04a7678ef544562e2
+SIZE (rubygem/atk-4.2.4.gem) = 15872