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/qtserialport/Manifest

@@ -0,0 +1,5 @@
+DIST qtserialport-everywhere-opensource-src-5.15.16.tar.xz 314732 BLAKE2B 2464d81ce8bafd82164b61586dbda7faf0258c28538356bc6449e439705e4bb1d4b5a18efe165c99cc79dfd1deaa4c6eddf55ae2fa448c7646c16a03ee6b6f99 SHA512 d386d528aacce7d4e015110d814e852511db83a3648bc68116e4d300168ac826e83a145d9dd38e4a40ec2d4fd48ba89ac1eb9558afb895f7b39271ad760f2b17
+DIST qtserialport-everywhere-opensource-src-5.15.17.tar.xz 316636 BLAKE2B 24037460b3c709f3b1b8e1dd43a7053cc3eafcf4b68c5da2b08632af0b788f7102f2b2145870f398c36af93212d3c6145ba41825a6ab8d8deeaa3978fa7607cc SHA512 1d9f53c705bae23f04198bf3b5ea42a004d436182efdeda40cba88145647d15eedc0db42a5716de234cae4cc22c758847d740bd3a277d1d27083ae1b31ca8bb4
+DIST qtserialport-everywhere-src-6.8.2.tar.xz 274700 BLAKE2B 0313a375a5aa4bb71ad91fb8eb44d7523c5ba180bf53c2c38df2b710675d8b0ff845590daa15ed4006b7b0b5dc5014cc9c83e1663e8ee1e0e47f7bcd1668c612 SHA512 45b0431c965c4194d51dd4ec98978a0a9a45c25e5dcc73283805eee9e4efa3c7430f8d4716b0df76285d3b14ecbdabb31dc4ddec04942cc16d68a9791989fbe8
+DIST qtserialport-everywhere-src-6.8.3.tar.xz 276532 BLAKE2B 607cdbb65391051000cbff60f5dc1dcbcfb0f4fd5d85bbbcf67a04e8a63a0b610cb51341cab22a1b5ec66bc5ef766339d276efb41a64919777b60a3e7a8a3a9f SHA512 343537aedd9c84dd5d6889d45babff181d7ef05927fd9cfdbb9389066f8860e2522bc059ca2c5c9af4c88bca255e0fc40b5eea84b93c970123a94afc803a638d
+DIST qtserialport-everywhere-src-6.9.0.tar.xz 278176 BLAKE2B 566f8c1670c45c772e60567845953f6766af2ddb58263eaace781ab84f2c577097cf4b35ee46bd215de848583daad7dc9231effcffc10c6c5abe10147f277243 SHA512 c491181a8e8b6f61bb69cfab314ba6380318907601e9c3477b324e2978eca58bd7fe75d6e68b4945efe20f81048ad230a5b78921af017150d5248ff7356b73a4

dev-qt/qtserialport/metadata.xml

@@ -0,0 +1,18 @@
+<?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>
+	<upstream>
+		<bugs-to>https://bugreports.qt.io/</bugs-to>
+		<doc>https://doc.qt.io/</doc>
+		<remote-id type="github">qt/qtserialport</remote-id>
+	</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/qtserialport/qtserialport-5.15.16.ebuild

@@ -0,0 +1,29 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+inherit qt5-build
+
+DESCRIPTION="Serial port abstraction library for the Qt5 framework"
+
+if [[ ${QT5_BUILD_TYPE} == release ]]; then
+	KEYWORDS="amd64 arm arm64 ~hppa ~loong ppc ppc64 ~riscv x86"
+fi
+
+IUSE=""
+
+DEPEND="
+	=dev-qt/qtcore-${QT5_PV}*
+	virtual/libudev:=
+"
+RDEPEND="${DEPEND}"
+
+src_prepare() {
+	# make sure we link against libudev
+	sed -i -e 's/:qtConfig(libudev)//' \
+		-e "s/\$\$QMAKE_LIBS_LIBUDEV/-ludev/" \
+		src/serialport/serialport-lib.pri || die
+
+	qt5-build_src_prepare
+}

dev-qt/qtserialport/qtserialport-5.15.17.ebuild

@@ -0,0 +1,29 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+inherit qt5-build
+
+DESCRIPTION="Serial port abstraction library for the Qt5 framework"
+
+if [[ ${QT5_BUILD_TYPE} == release ]]; then
+	KEYWORDS="~amd64 ~arm ~arm64 ~hppa ~loong ~ppc ~ppc64 ~riscv ~x86"
+fi
+
+IUSE=""
+
+DEPEND="
+	=dev-qt/qtcore-${QT5_PV}*
+	virtual/libudev:=
+"
+RDEPEND="${DEPEND}"
+
+src_prepare() {
+	# make sure we link against libudev
+	sed -i -e 's/:qtConfig(libudev)//' \
+		-e "s/\$\$QMAKE_LIBS_LIBUDEV/-ludev/" \
+		src/serialport/serialport-lib.pri || die
+
+	qt5-build_src_prepare
+}