user/libixion: Update to 0.19.0

Use upstream dist tarball, ala mdds.
Update needed for new mdds.

Also, restore pre-GCC 13 x87 FPU behavior

Closes: #1214

user/libixion/APKBUILD

 # Contributor: Timo Teräs <timo.teras@iki.fi>
 # Maintainer: Max Rees <maxcrees@me.com>
 pkgname=libixion
-pkgver=0.17.0
+pkgver=0.19.0
 pkgrel=0
 pkgdesc="A general purpose formula parser & interpreter"
 url="https://gitlab.com/ixion/ixion"
@@ -9,14 +9,15 @@ arch="all"
 license="MPL-2.0"
 depends=""
 depends_dev="mdds"
-makedepends="$depends_dev boost-dev spdlog autoconf automake libtool cmd:which"
+makedepends="$depends_dev boost-dev spdlog"
 subpackages="$pkgname-dev"
-source="https://gitlab.com/ixion/ixion/-/archive/$pkgver/ixion-$pkgver.tar.bz2"
-
-builddir="$srcdir/ixion-$pkgver"
+source="https://gitlab.com/api/v4/projects/ixion%2Fixion/packages/generic/source/$pkgver/$pkgname-$pkgver.tar.xz"
 
 build() {
-	./autogen.sh \
+	# GCC 13 changed default fp precision behavior. (#1193, #1214)
+	export CXXFLAGS="${CXXFLAGS} -fexcess-precision=fast"
+
+	./configure \
 		--build=$CBUILD \
 		--host=$CHOST \
 		--prefix=/usr \
@@ -41,4 +42,4 @@ dev() {
 	mv "$pkgdir"/usr/bin "$subpkgdir"/usr
 }
 
-sha512sums="f6216b06342c43ddf937bcc7eb3104e500bc10d6798f9b24c92c423bda575ac3f7bdae68bb81b2826c164e7dd19bbef940a3848581c5f9e969a6e70934e58d0a  ixion-0.17.0.tar.bz2"
+sha512sums="f06edbcf5ae7459a46e01273952ce6fbc4e8f2b7782c7e07645dc30e102f20f542e449acafc26484765207b10656e0b350f4108cbf1e03947ee7267254cf6f97  libixion-0.19.0.tar.xz"