harfbuzz: fix update builds on macOS.

Set DYLD_LIBRARY_PATH to find newly built libraries even if an earlier
version is already installed.

fonts/harfbuzz/distinfo

@@ -1,6 +1,7 @@
-$NetBSD: distinfo,v 1.131 2023/07/19 15:48:31 wiz Exp $
+$NetBSD: distinfo,v 1.132 2023/08/22 16:33:48 schmonz Exp $
 
 BLAKE2s (harfbuzz-8.0.1.tar.xz) = a8925d392f90c2b21d3e50789a7e5bb95fa443294644d9a0a8d297c725f1e826
 SHA512 (harfbuzz-8.0.1.tar.xz) = e1292f059b07a5aa2f3fbf345b893209cac895c461b4abf30b8b76bcd03c79dd09f911450293403070e1a0bb08496a7f37693ba5a62a9d423dd6ba55e744444d
 Size (harfbuzz-8.0.1.tar.xz) = 18792332 bytes
 SHA1 (patch-meson.build) = ad46bbe61df28b71e7619847920935a398e16fd1
+SHA1 (patch-src_meson.build) = 5b46f9933d5dea1f842fccf63eb92faae1f7c90f

fonts/harfbuzz/patches/patch-src_meson.build

@@ -0,0 +1,18 @@
+$NetBSD: patch-src_meson.build,v 1.1 2023/08/22 16:33:48 schmonz Exp $
+
+Generate .gir using the built libraries, even if an earlier version is
+already installed. Fixes update builds on macOS when e.g. new symbols
+are introduced.
+
+--- src/meson.build.orig	2023-07-12 05:28:28.000000000 +0000
++++ src/meson.build
+@@ -879,6 +879,9 @@ if have_gobject
+       export_packages: ['harfbuzz-gobject', 'harfbuzz'],
+       header: 'hb-gobject.h',
+       install: true,
++      env: {
++        'DYLD_LIBRARY_PATH': meson.project_build_root() + '/src'
++      },
+       extra_args:  ['--cflags-begin',
+                     '-DHB_NO_SINGLE_HEADER_ERROR',
+                     '-DHAVE_GOBJECT',