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/qtwidgets/Manifest

@@ -0,0 +1,5 @@
+DIST qtbase-5.15-gentoo-patchset-6.tar.xz 8288 BLAKE2B ad9695a528345dd3b8e9ce72b7bdfe8f744f16685a567bbc7862ba6c28e5a426260cb0b73e2573cb3a6f16f1785786898ffb44c90f5d75354b97e5756c7573db SHA512 97bc4d5375e1750a5578439ff320ee2e5e929df1dafe56b4e86f2de8ad26c91dc4002e45ad75d9f936347d49b9f54c0c42f8fc2cb7dfd4f54bf08a210b3bc720
+DIST qtbase-5.15.18-gentoo-kde-1.tar.xz 450532 BLAKE2B 172732fe6a2f7dd4718b224d8a8ba7b182ded24f74ee38545d20a17364757153b399cae82b40f425e72b2587ec432f024868078edfe95280242211a040ddd9f6 SHA512 e0257171cf723cb6208a06f28fc95fa07d1239ea9dd3daa79d362146aa53e008398c9e1d95443b84d6d71b835a3f010b957e748f3ec23b77a588d6b372fd0c47
+DIST qtbase-everywhere-opensource-src-5.15.18.tar.xz 51492796 BLAKE2B a02f13f2ae8d3994fe5e3fa5b3751cb2981c3203cc4f3859dd4398d6a62101772885acb0c7b1f830ba8e9fbdd64ecfdb2a6074bfedd1bd372b4fc9ceb747467d SHA512 d39c831e6f3ddcd6a50f103ff60a0700b451f137782249508b7447a80066e3e9259c9b5038e6077ccf8df06b6afefec232c3c4dd331d85765089c92571708206
+EBUILD qtwidgets-5.15.18.ebuild 1196 BLAKE2B d27a2e5133f0434f648499700fc434fcd4e1f8cc03341aea7a59d008ffebdf8dbc882ef0476f4e8a2ba505834206d96ab71f4e948c00e2ac81102f3a753bb954 SHA512 5d22723e4b7c7dea59533d5baafaded8a1f6eeb036d74c4a4cc82ebbded1147691e54af16ecf82ab66b2a43d4e260183e2dc0383076c7196982aab4991f5ab68
+MISC metadata.xml 559 BLAKE2B 3ea80a5e419db32987d68d7e5033fa75fa0ff22b31b0842fd7ead902172cbe83650b0bbdf8657a57e428726e7cdf114d9011bd16066c080bc5f6ecb3f691d42c SHA512 51172365a186fbca09651bfd751284960dda4036390af2afab9812a7ae3fabdd9d60a336dee3cfc5e3d133a0216bf77e29660b9cdee2f0bcd2ce43c27297bdb1

dev-qt/qtwidgets/metadata.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE pkgmetadata SYSTEM "https://www.gentoo.org/dtd/metadata.dtd">
+<pkgmetadata>
+	<maintainer type="project">
+		<email>qt@gentoo.org</email>
+		<name>Gentoo Qt Project</name>
+	</maintainer>
+	<use>
+		<flag name="gtk">Build the GTK platform theme plugin</flag>
+	</use>
+	<upstream>
+		<bugs-to>https://bugreports.qt.io/</bugs-to>
+		<doc>https://doc.qt.io/</doc>
+	</upstream>
+	<slots>
+		<subslots>
+			Must only be used by packages that are known to use private parts of the Qt API.
+		</subslots>
+	</slots>
+</pkgmetadata>

dev-qt/qtwidgets/qtwidgets-5.15.18.ebuild

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+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+if [[ ${PV} != *9999* ]]; then
+	QT5_KDEPATCHSET_REV=1
+	KEYWORDS="amd64 arm arm64 ~hppa ~loong ppc ppc64 ~riscv x86"
+fi
+
+QT5_MODULE="qtbase"
+inherit qt5-build
+
+DESCRIPTION="Set of components for creating classic desktop-style UIs for the Qt5 framework"
+
+# keep IUSE defaults in sync with qtgui
+IUSE="dbus gles2-only gtk +png +X"
+REQUIRED_USE="gtk? ( dbus )"
+
+DEPEND="
+	=dev-qt/qtcore-${QT5_PV}*:5=
+	=dev-qt/qtgui-${QT5_PV}*:5=[gles2-only=,png=,X?]
+	dbus? ( =dev-qt/qtdbus-${QT5_PV}* )
+	gtk? (
+		dev-libs/glib:2
+		=dev-qt/qtgui-${QT5_PV}*:5=[dbus]
+		x11-libs/gtk+:3[X]
+		x11-libs/libX11
+		x11-libs/pango
+	)
+"
+RDEPEND="${DEPEND}"
+
+QT5_TARGET_SUBDIRS=(
+	src/tools/uic
+	src/widgets
+	src/plugins/platformthemes
+)
+
+QT5_GENTOO_CONFIG=(
+	dbus:xdgdesktopportal:
+	gtk:gtk3:
+	::widgets
+	!:no-widgets:
+)
+
+QT5_GENTOO_PRIVATE_CONFIG=(
+	:widgets
+)
+
+src_configure() {
+	local myconf=(
+		-opengl $(usex gles2-only es2 desktop)
+		$(usev dbus -dbus-linked)
+		$(qt_use gtk)
+		-gui
+		$(qt_use png libpng system)
+		-widgets
+		$(qt_use X xcb)
+		$(usev X '-xcb-xlib -xkbcommon')
+	)
+	qt5-build_src_configure
+}