units: set DefaultDependencies=no for veritysetup slice

This mimics what we already have for cryptsetup services: the slice they
are placed in (they have their own slice since that's what we do by
default for instantiated services) shouldn't conflict with
shutdown.target, so that veritysetup services can stay around until the
very end (which is what we want for the root and usr verity volumes).

It's literally just a copy of the same unit we already have for
cryptsetup, just with an updated description string.

units/meson.build

@@ -96,6 +96,7 @@ units = [
         ['sysinit.target',                      ''],
         ['syslog.socket',                       ''],
         ['system-systemd\\x2dcryptsetup.slice', 'HAVE_LIBCRYPTSETUP'],
+        ['system-systemd\\x2dveritysetup.slice','HAVE_LIBCRYPTSETUP'],
         ['system-update.target',                ''],
         ['system-update-pre.target',            ''],
         ['system-update-cleanup.service',       ''],

units/system-systemd\x2dcryptsetup.slice

@@ -8,6 +8,6 @@
 #  (at your option) any later version.
 
 [Unit]
-Description=Cryptsetup Units Slice
+Description=Encrypted Volume Units Service Slice
 Documentation=man:systemd-cryptsetup@.service(8)
 DefaultDependencies=no

units/system-systemd\x2dveritysetup.slice

@@ -0,0 +1,13 @@
+#  SPDX-License-Identifier: LGPL-2.1-or-later
+#
+#  This file is part of systemd.
+#
+#  systemd is free software; you can redistribute it and/or modify it
+#  under the terms of the GNU Lesser General Public License as published by
+#  the Free Software Foundation; either version 2.1 of the License, or
+#  (at your option) any later version.
+
+[Unit]
+Description=Verity Protection Service Slice
+Documentation=man:systemd-cryptsetup@.service(8)
+DefaultDependencies=no