Include "version.cuh" from "util_namespace.cuh" so that we can include a header

that has always existed in Thrust when checking for older versions of CUB.

Bug 2950372

Author: brycelelbach

cub/util_namespace.cuh

@@ -33,6 +33,8 @@
 
 #pragma once
 
+#include "version.cuh"
+
 // For example:
 //#define CUB_NS_PREFIX namespace thrust{ namespace detail {
 //#define CUB_NS_POSTFIX } }