update systemd & dbus dependencies

Update the outdated systemd and dbus dependencies which are now provided
as go modules.  This will further tighten our dependencies and releases
and pave the way for the upcoming auto-update feature.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

vendor/github.com/godbus/dbus/v5/auth_anonymous.go

@@ -0,0 +1,16 @@
+package dbus
+
+// AuthAnonymous returns an Auth that uses the ANONYMOUS mechanism.
+func AuthAnonymous() Auth {
+	return &authAnonymous{}
+}
+
+type authAnonymous struct{}
+
+func (a *authAnonymous) FirstData() (name, resp []byte, status AuthStatus) {
+	return []byte("ANONYMOUS"), nil, AuthOk
+}
+
+func (a *authAnonymous) HandleData(data []byte) (resp []byte, status AuthStatus) {
+	return nil, AuthError
+}