devel/icu: temporarily switch to GitHub

- Release downloads are published way later
- LFS mainly affected ICU4J (Java API) while this port builds ICU4C (C/C++ API)
- docs/processes/release/tasks/publish/index.md says LFS is nowadays supported by GitHub archives

PR:		262654

devel/icu/Makefile

@@ -1,13 +1,11 @@
 # Created by: dwm
 
 PORTNAME=	icu
-DISTVERSION=	70_1
+DISTVERSIONPREFIX=	release-
+DISTVERSION=	70-1
 PORTREVISION?=	1 # keep for icu-lx
 PORTEPOCH?=	1
 CATEGORIES?=	devel
-MASTER_SITES=	https://github.com/unicode-org/${PORTNAME}/releases/download/release-${DISTVERSION:S/rc/-&/:S/_/-/g}/ \
-		SF/${PORTNAME}/${PORTNAME:tu}4C/${PORTVERSION}
-DISTNAME=	icu4c-${DISTVERSION}-src
 
 MAINTAINER=	office@FreeBSD.org
 COMMENT?=	International Components for Unicode (from IBM)
@@ -31,7 +29,9 @@ TEST_TARGET=	check
 CPE_VENDOR=	${PORTNAME}-project
 CPE_PRODUCT=	international_components_for_unicode
 USE_LDCONFIG=	yes
-WRKSRC=		${WRKDIR}/icu/source
+USE_GITHUB=	yes
+GH_ACCOUNT=	unicode-org
+WRKSRC_SUBDIR=	icu4c/source
 
 ICUMAJOR=	${PORTVERSION:C/\..*//}
 PLIST_SUB+=	ICUMAJOR=${ICUMAJOR} ICUVER=${PORTVERSION:C/r.?/1/}

devel/icu/distinfo

@@ -1,3 +1,3 @@
 TIMESTAMP = 1635437097
-SHA256 (icu4c-70_1-src.tgz) = 8d205428c17bf13bb535300669ed28b338a157b1c01ae66d31d0d3e2d47c3fd5
-SIZE (icu4c-70_1-src.tgz) = 25449582
+SHA256 (unicode-org-icu-release-70-1_GH0.tar.gz) = f30d670bdc03ba999638a2d2511952ab94adf204d0e14898666f2e0cacb7fef1
+SIZE (unicode-org-icu-release-70-1_GH0.tar.gz) = 65661187