systemd: remove compatibility patch for legacy Plasma

pkgs/os-specific/linux/systemd/0018-logind-seat-debus-show-CanMultiSession-again.patch

@@ -1,26 +0,0 @@
-From beb594ff3bceb95598ffa8ec47c31bacb2449473 Mon Sep 17 00:00:00 2001
-From: Thomas Tuegel <ttuegel@mailbox.org>
-Date: Mon, 26 Oct 2020 21:21:38 +0100
-Subject: [PATCH 18/19] logind-seat-debus: show CanMultiSession again
-
-Fixes the "switch user" function in Plasma < 5.20.
----
- src/login/logind-seat-dbus.c | 2 +-
- 1 file changed, 1 insertion(+), 1 deletion(-)
-
-diff --git a/src/login/logind-seat-dbus.c b/src/login/logind-seat-dbus.c
-index cceb3b1d2d..94b4723bb9 100644
---- a/src/login/logind-seat-dbus.c
-+++ b/src/login/logind-seat-dbus.c
-@@ -419,7 +419,7 @@ static const sd_bus_vtable seat_vtable[] = {
- 
-         SD_BUS_PROPERTY("Id", "s", NULL, offsetof(Seat, id), SD_BUS_VTABLE_PROPERTY_CONST),
-         SD_BUS_PROPERTY("ActiveSession", "(so)", property_get_active_session, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
--        SD_BUS_PROPERTY("CanMultiSession", "b", property_get_const_true, 0, SD_BUS_VTABLE_PROPERTY_CONST|SD_BUS_VTABLE_HIDDEN),
-+        SD_BUS_PROPERTY("CanMultiSession", "b", property_get_const_true, 0, SD_BUS_VTABLE_PROPERTY_CONST),
-         SD_BUS_PROPERTY("CanTTY", "b", property_get_can_tty, 0, SD_BUS_VTABLE_PROPERTY_CONST),
-         SD_BUS_PROPERTY("CanGraphical", "b", property_get_can_graphical, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
-         SD_BUS_PROPERTY("Sessions", "a(so)", property_get_sessions, 0, 0),
--- 
-2.32.0
-

pkgs/os-specific/linux/systemd/default.nix

@@ -155,7 +155,6 @@ stdenv.mkDerivation {
     ./0015-systemd-sleep-execute-scripts-in-etc-systemd-system-.patch
     ./0016-kmod-static-nodes.service-Update-ConditionFileNotEmp.patch
     ./0017-path-util.h-add-placeholder-for-DEFAULT_PATH_NORMAL.patch
-    ./0018-logind-seat-debus-show-CanMultiSession-again.patch
     ./0019-pkg-config-derive-prefix-from-prefix.patch
 
     # In v249 a bunch of meson files had been touched as part of the migration to