Allow co-installation of systemd-sysusers-standalone and systemd

Previously, /usr/bin/systemd-sysusers was provided by both systemd and
systemd-standalone-sysusers, creating a file conflict, and the packages
declared Conflicts. This changed when systemd-sysusers was split out to a
separate subpackage. So we don't need the Conflicts and can allow a "cross
installation" of systemd-sysusers-standalone and and the other "normal"
systemd subpackages.

This should solve https://bugzilla.redhat.com/show_bug.cgi?id=2344322 without
requiring changes in the container definitions. (Though those changes probably
should be made anyway. If we end up installing systemd, we probably want to use
shared systemd-sysusers, to avoid wasting space.)

systemd.spec

@@ -254,7 +254,10 @@ Requires:       %{name}-libs%{_isa} = %{version}-%{release}
 %{?fedora:Recommends:     %{name}-networkd = %{version}-%{release}}
 %{?fedora:Recommends:     %{name}-resolved = %{version}-%{release}}
 Requires:       %{name}-shared%{_isa} = %{version}-%{release}
-Requires:       %{name}-sysusers%{_isa} = %{version}-%{release}
+Requires:       /usr/bin/systemd-sysusers
+# The standalone version doesn't Provide the _isa suffix,
+# so this biases towards the common version.
+Recommends:     %{name}-sysusers%{_isa} = %{version}-%{release}
 Recommends:     diffutils
 Requires:       (util-linux-core or util-linux)
 Provides:       /bin/systemctl
@@ -710,7 +713,6 @@ main systemd package and is meant for use on systems without systemd.
 %package standalone-sysusers
 Summary:       Standalone systemd-sysusers binary for use on systems without systemd
 Provides:      %{name}-sysusers = %{version}-%{release}
-Conflicts:     %{name}
 Suggests:      coreutils-single
 RemovePathPostfixes: .standalone