doc: Updated x11/gtksourceview5 to 5.20.0

Author: ryoon

doc/CHANGES-2026

@@ -1,4 +1,4 @@
-$NetBSD: CHANGES-2026,v 1.3028 2026/05/14 17:42:49 ryoon Exp $
+$NetBSD: CHANGES-2026,v 1.3029 2026/05/14 17:54:22 ryoon Exp $
 
 Changes to the packages collection and infrastructure in 2026:
 
@@ -4642,3 +4642,4 @@ Changes to the packages collection and infrastructure in 2026:
 	Updated devel/at-spi2-core to 2.60.3 [ryoon 2026-05-14]
 	Updated multimedia/libaom to 3.13.3 [ryoon 2026-05-14]
 	Updated x11/gtk3 to 3.24.52 [ryoon 2026-05-14]
+	Updated x11/gtksourceview5 to 5.20.0 [ryoon 2026-05-14]