Add dev-qt from an older version of the gentoo repo

Qt5 has been removed, we restore it since we still use it.

dev-qt/qt5compat/qt5compat-6.9.9999.ebuild

@@ -0,0 +1,38 @@
+# Copyright 2023-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+inherit qt6-build
+
+DESCRIPTION="Qt module containing the unsupported Qt 5 APIs"
+
+if [[ ${QT6_BUILD_TYPE} == release ]]; then
+	KEYWORDS="~amd64 ~arm ~arm64 ~hppa ~loong ~ppc ~ppc64 ~riscv ~x86"
+fi
+
+IUSE="+gui icu qml"
+
+RDEPEND="
+	~dev-qt/qtbase-${PV}:6[gui=,icu=,network,xml]
+	icu? ( dev-libs/icu:= )
+	!icu? ( virtual/libiconv )
+	qml? (
+		~dev-qt/qtdeclarative-${PV}:6
+		~dev-qt/qtshadertools-${PV}:6
+	)
+"
+DEPEND="${RDEPEND}"
+
+src_configure() {
+	local mycmakeargs=(
+		$(cmake_use_find_package qml Qt6Quick)
+	)
+
+	qt6-build_src_configure
+}
+
+src_test() {
+	# tst_qxmlinputsource sometimes hang without -j1
+	qt6-build_src_test -j1
+}