disable the test for clang-22 until the fix is included in libc++ CI image

Author: huixie90

libcxx/test/std/atomics/atomics.types.generic/cas_non_power_of_2.pass.cpp

@@ -12,13 +12,14 @@
 // XFAIL: clang-20, clang-21, apple-clang-15, apple-clang-16, apple-clang-17
 // UNSUPPORTED: c++03
 
+// TODO: remove the UNSUPPORTED clang-22 once libc++ CI's clang is updated to include
+// the fix https://github.com/llvm/llvm-project/pull/78707
+// UNSUPPORTED: clang-22
+
 #include <atomic>
 #include <cstring>
 #include <cassert>
 
-// todo remove after debugging
-#include <iostream>
-
 template <int Size>
 struct S {
   char data[Size];