system/libarchive: add zst support (req'd for new CMake)

system/libarchive/APKBUILD

@@ -2,14 +2,14 @@
 # Maintainer: A. Wilcox <awilfox@adelielinux.org>
 pkgname=libarchive
 pkgver=3.4.0
-pkgrel=0
+pkgrel=1
 pkgdesc="Library for creating and reading streaming archives"
 url="https://libarchive.org/"
 arch="all"
 options="!check"  # needs EUC-JP and KOI8R support in iconv
 license="BSD-2-Clause AND BSD-3-Clause AND Public-Domain"
 makedepends="zlib-dev bzip2-dev xz-dev lz4-dev acl-dev openssl-dev expat-dev
-	attr-dev"
+	attr-dev zstd-dev"
 subpackages="$pkgname-dev $pkgname-doc $pkgname-tools"
 source="https://github.com/libarchive/libarchive/releases/download/v$pkgver/$pkgname-$pkgver.tar.gz
 	seek-error.patch