app-text/libqxp: remove bundled ax_cxx_compile_stdcxx.m4

Bundled version is serial 7.
`dev-build/autoconf-archive-2024.10.16-r2` ships serial 25.

Closes: https://bugs.gentoo.org/977602
Signed-off-by: Paul Zander <negril.nx+gentoo@gmail.com>
Signed-off-by: Sam James <sam@gentoo.org>

app-text/libqxp/libqxp-0.0.3.ebuild

@@ -3,6 +3,8 @@
 
 EAPI=9
 
+inherit autotools
+
 DESCRIPTION="Library parsing QuarkXpress documents"
 HOMEPAGE="https://wiki.documentfoundation.org/DLP/Libraries/libqxp"
 SRC_URI="https://dev-www.libreoffice.org/src/${PN}/${P}.tar.xz"
@@ -26,6 +28,15 @@ BDEPEND="
 	doc? ( app-text/doxygen )
 "
 
+src_prepare() {
+	default
+
+	# old bundled version
+	rm m4/ax_cxx_compile_stdcxx.m4 || die
+
+	eautoreconf
+}
+
 src_configure() {
 	local myeconfargs=(
 		--disable-weffc