devel/rubygem-holidays: Update to 8.6.0

Changes:	https://github.com/holidays/holidays/releases
		https://github.com/holidays/holidays/blob/master/CHANGELOG.md

devel/rubygem-holidays/Makefile

 PORTNAME=	holidays
-PORTVERSION=	8.5.0
+PORTVERSION=	8.6.0
 CATEGORIES=	devel rubygems
 MASTER_SITES=	RG
 

devel/rubygem-holidays/distinfo

-TIMESTAMP = 1642102633
-SHA256 (rubygem/holidays-8.5.0.gem) = c21e45328e77fdade3ba7fe4899114c58181305df9f044199722c1b1e9840336
-SIZE (rubygem/holidays-8.5.0.gem) = 152064
+TIMESTAMP = 1663672970
+SHA256 (rubygem/holidays-8.6.0.gem) = d8f67e5965a642a2ff64f9b031327cfb9b7adb8779d51403c65f79bba93cc8ed
+SIZE (rubygem/holidays-8.6.0.gem) = 153088