[SYCL]{NFC] Add thread library linking to multithread_write_accessor (intel#15331)

Author: sergey-semenov

sycl/test-e2e/Regression/multithread_write_accessor.cpp

@@ -1,4 +1,4 @@
-// RUN: %{build} -o %t.out
+// RUN: %{build} -o %t.out %threads_lib
 // RUN: %{run} %t.out
 #include <sycl/detail/core.hpp>