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/qtquick3d/qtquick3d-6.9.9999.ebuild

@@ -0,0 +1,56 @@
+# Copyright 2021-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+QT6_HAS_STATIC_LIBS=1
+inherit qt6-build
+
+DESCRIPTION="Qt module and API for defining 3D content in Qt QuickTools"
+
+if [[ ${QT6_BUILD_TYPE} == release ]]; then
+	KEYWORDS="~amd64 ~arm ~arm64 ~loong ~ppc64 ~riscv ~x86"
+elif [[ ${QT6_BUILD_TYPE} == live ]]; then
+	EGIT_SUBMODULES=() # skip qtquick3d-assimp
+fi
+
+IUSE="opengl vulkan"
+
+RDEPEND="
+	~dev-qt/qtbase-${PV}:6[concurrent,gui,opengl=,vulkan=,widgets]
+	~dev-qt/qtdeclarative-${PV}:6
+	~dev-qt/qtquicktimeline-${PV}:6
+	~dev-qt/qtshadertools-${PV}:6
+	media-libs/assimp:=
+	sys-libs/zlib:=
+"
+DEPEND="
+	${RDEPEND}
+	test? ( ~dev-qt/qtbase-${PV}:6[network] )
+	vulkan? ( dev-util/vulkan-headers )
+"
+BDEPEND="
+	~dev-qt/qtshadertools-${PV}:6
+"
+
+PATCHES=(
+	"${FILESDIR}"/${PN}-6.6.2-gcc14.patch
+	"${FILESDIR}"/${PN}-6.6.2-x32abi.patch
+)
+
+CMAKE_SKIP_TESTS=(
+	# needs off-by-default assimp[collada] that is masked on some profiles,
+	# not worth the extra trouble
+	tst_qquick3dassetimport
+)
+
+src_configure() {
+	local mycmakeargs=(
+		# TODO: if someone wants it, openxr should likely have its own
+		# USE and be packaged rather than use the bundled copy (if use
+		# bundled, note need to setup python-any-r1)
+		-DQT_FEATURE_quick3dxr_openxr=OFF
+	)
+
+	qt6-build_src_configure
+}