Cleanup: Cycles: Use gtest header instead of Blender test header

To avoid conflicts with glog logging macros, and because there is just no
need to have this dependency.

Pull Request: https://projects.blender.org/blender/blender/pulls/143719

intern/cycles/test/util_aligned_malloc_test.cpp

@@ -2,7 +2,7 @@
  *
  * SPDX-License-Identifier: Apache-2.0 */
 
-#include "testing/testing.h"
+#include <gtest/gtest.h>
 
 #include "util/aligned_malloc.h"