virtual/dist-kernel: add 5.18.4, drop 5.17.7 and 5.17.8

Signed-off-by: Alfred Wingate <parona@protonmail.com>

virtual/dist-kernel/dist-kernel-5.17.8.ebuild

@@ -1,21 +0,0 @@
-# Copyright 2022 Gentoo Authors
-# Distributed under the terms of the GNU General Public License v2
-
-EAPI=8
-
-DESCRIPTION="Virtual to depend on any Distribution Kernel"
-HOMEPAGE=""
-SRC_URI=""
-
-LICENSE=""
-SLOT="0/${PV}"
-KEYWORDS="~amd64"
-
-RDEPEND="
-	|| (
-		~sys-kernel/gentoo-kernel-${PV}
-		~sys-kernel/gentoo-kernel-bin-${PV}
-		~sys-kernel/vanilla-kernel-${PV}
-		~sys-kernel/xanmod-kernel-${PV}
-		~sys-kernel/xanmod-kernel-bin-${PV}
-		)"