devel/llvm17: update to 17.0.3

See the release announcement for changes:
  https://discourse.llvm.org/t/llvm-17-0-3-released/74172

devel/llvm17/Makefile

 PORTNAME=	llvm
-DISTVERSION=	17.0.2
+DISTVERSION=	17.0.3
 PORTREVISION=	0
 CATEGORIES=	devel lang
 MASTER_SITES=	https://github.com/llvm/llvm-project/releases/download/llvmorg-${DISTVERSION:S/rc/-rc/}/ \

devel/llvm17/distinfo

-TIMESTAMP = 1696343306
-SHA256 (llvm-project-17.0.2.src.tar.xz) = 351562b14d42fcefcbf00cc1f327680a1062bbbf67a1e1ca6acb64c473b06394
-SIZE (llvm-project-17.0.2.src.tar.xz) = 127833708
+TIMESTAMP = 1697573268
+SHA256 (llvm-project-17.0.3.src.tar.xz) = be5a1e44d64f306bb44fce7d36e3b3993694e8e6122b2348608906283c176db8
+SIZE (llvm-project-17.0.3.src.tar.xz) = 127843636