dev-tcltk/tclxml: add dev-libs/libxml2 subslot op for incoming ABI break

Signed-off-by: Alfred Wingate <parona@protonmail.com>
Signed-off-by: Alfredo Tupone <tupone@gentoo.org>

dev-tcltk/tclxml/tclxml-3.3.1-r3.ebuild

@@ -1,4 +1,4 @@
-# Copyright 1999-2024 Gentoo Authors
+# Copyright 1999-2025 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=8
@@ -10,6 +10,7 @@ DESCRIPTION="Pure Tcl implementation of an XML parser"
 HOMEPAGE="https://github.com/flightaware/TclXML"
 SRC_URI="https://github.com/flightaware/TclXML/archive/refs/tags/v${PV}.tar.gz
 	-> ${MYP}.tar.gz"
+S="${WORKDIR}"/${MYP}
 
 LICENSE="BSD"
 SLOT="0"
@@ -18,7 +19,7 @@ IUSE="debug threads"
 
 DEPEND="
 	>=dev-lang/tcl-8.2:=
-	>=dev-libs/libxml2-2.6.9
+	>=dev-libs/libxml2-2.6.9:=
 	dev-libs/libxslt
 	>=dev-tcltk/tcllib-1.2
 	dev-libs/expat"
@@ -36,8 +37,6 @@ PATCHES=(
 	"${FILESDIR}"/${P}-funcPointer.patch
 )
 
-S="${WORKDIR}"/${MYP}
-
 src_configure() {
 	local myconf=""