systemd: drop usr-merge

[caleb: adding context] This enables using systemd with split /usr, it is intended to be a temporary solution to allow our systemd work to continue while the /usr merge is implemented upstream in Alpine. We previously attempted to work around this by patching apk-tools, but it's become clear that this is not a viable solution, and given the rate at which /usr merges patches are getting merged in Alpine it isn't worth investing in it further. The /usr merge is still a hard requirement for us and will be a blocker to ship systemd in postmarketOS stable.

---

one way to test this:

git checkout origin/jane400/systemd/split-usr-bin
pmbootstrap config mirrors.systemd "none"
pmbootstrap repo_bootstrap systemd
# can't activate the mirrors.systemd back on, apk-tools would get pulled in
pmbootstrap install

extra-repos/systemd/apk-tools/APKBUILD

-# Forked from Alpine to support usr-merge:
-# https://gitlab.alpinelinux.org/alpine/apk-tools/-/merge_requests/155
-
-pkgname=apk-tools
-pkgver=9992.14
-_pkgver=2.14.0
-pkgrel=7
-pkgdesc="Alpine Package Keeper - package manager for alpine"
-arch="all"
-url="https://gitlab.alpinelinux.org/alpine/apk-tools"
-license="GPL-2.0-only"
-subpackages="$pkgname-dbg $pkgname-dev $pkgname-static $pkgname-doc $pkgname-zsh-completion"
-# Musl 1.2 introduced new ABI for time64 => upgrading apk-tools
-# while staying on musl <1.2 causes missing symbols
-# starting with musl 1.2.3_git (pre 1.2.3), we added DT_RELR
-# it is possible for old systems to upgrade, and apk-tools would upgrade first,
-# which would upgrade to a binary that cannot run until musl is upgraded.
-# forcing this constraint makes apk upgrade musl as part of the 'critical' transaction,
-# and update musl first.
-depends="musl>=1.2.3_git20230424"
-makedepends_build="openssl>3 lua5.3 lua5.3-lzlib scdoc"
-makedepends_host="zlib-dev openssl-dev zlib-static openssl-libs-static linux-headers"
-makedepends="$makedepends_build $makedepends_host lua-dev"
-_lua="no"
-if [ "$CBUILD" = "$CHOST" ]; then
-	_lua="lua5.3"
-	subpackages="$subpackages $_lua-apk:luaapk"
-	makedepends="$makedepends $_lua-dev"
-
-	# ca-certificates-bundle needed for https certificate validation
-	depends="$depends ca-certificates-bundle"
-fi
-
-_commit="5f12ed34afdc52bd24778b9331a3fa3a1cb38f83"
-source="https://gitlab.com/postmarketOS/apk-tools/-/archive/$_commit/apk-tools-$_commit.tar.gz
-	_apk
-	"
-builddir="$srcdir/$pkgname-$_commit"
-
-# secfixes:
-#   2.12.6-r0:
-#     - CVE-2021-36159
-#   2.12.5-r0:
-#     - CVE-2021-30139
-
-prepare() {
-	default_prepare
-	sed -i -e 's:-Werror::' Make.rules
-	echo "FULL_VERSION=$_pkgver-r$pkgrel" > config.mk
-}
-
-build() {
-	make LUA="$_lua"
-	make static LUA="$_lua"
-}
-
-check() {
-	make check LUA="$_lua"
-}
-
-package() {
-	make DESTDIR="$pkgdir" LUA="$_lua" install
-	install -d "$pkgdir"/var/lib/apk \
-		"$pkgdir"/lib/apk/exec \
-		"$pkgdir"/etc/apk/keys \
-		"$pkgdir"/etc/apk/protected_paths.d
-
-	install -Dm644 "$srcdir"/_apk "$pkgdir"/usr/share/zsh/site-functions/_apk
-	rm -r "$pkgdir"/usr/share/doc
-}
-
-static() {
-	pkgdesc="Alpine Package Keeper - static binary"
-	install -Dm755 "$builddir"/src/apk.static \
-		"$subpkgdir"/sbin/apk.static
-
-	# lets sign the static binary so it can be vefified from distros
-	# that does not have apk-tools
-	local abuild_conf=${ABUILD_CONF:-"/etc/abuild.conf"}
-	local abuild_home=${ABUILD_USERDIR:-"$HOME/.abuild"}
-	local abuild_userconf=${ABUILD_USERCONF:-"$abuild_home/abuild.conf"}
-	[ -f "$abuild_userconf" ] && . "$abuild_userconf"
-	local privkey="$PACKAGER_PRIVKEY"
-	local pubkey=${PACKAGER_PUBKEY:-"$privkey.pub"}
-	local keyname=${pubkey##*/}
-	${CROSS_COMPILE}strip "$subpkgdir"/sbin/apk.static
-	openssl dgst -sha1 -sign "$privkey" \
-		-out "$subpkgdir"/sbin/apk.static.SIGN.RSA.$keyname \
-		"$subpkgdir"/sbin/apk.static
-}
-
-luaapk() {
-	pkgdesc="Lua module for apk-tools"
-	mkdir -p "$subpkgdir"/usr/
-	mv "$pkgdir"/usr/lib "$subpkgdir"/usr/lib/
-}
-
-sha512sums="
-ff52a3b2221e3894761ff706f3cd0b03a04c555bf0007e189831ee1a394944716fd63b18e8fae7471c9663c87126a648042e0481e099073df1fa5ddcacdfc761  apk-tools-5f12ed34afdc52bd24778b9331a3fa3a1cb38f83.tar.gz
-7870676720f5007eee9482786e02246f8e3474afb90e76c9c83aebe914747a8e007b5d2eed6441933f4922024b3f0664db270f21981ad6c2db877a110b0cd79e  _apk
-"