[libc++] Disable test which timeouts on ARM with sanitizers

Introduced with cf0f6a1 (llvm#70020).

https://lab.llvm.org/buildbot/#/builders/237/builds/5145
https://lab.llvm.org/buildbot/#/builders/236/builds/7004
https://lab.llvm.org/buildbot/#/builders/239/builds/4269

Sometimes it passes with Asan but it's extemly slow

```
Slowest Tests:
1388.61s: llvm-libc++-shared.cfg.in :: std/experimental/simd/simd.reference/reference_assignment.pass.cpp
309.42s:  llvm-libc++-shared.cfg.in :: std/containers/sequences/deque/deque.modifiers/insert_size_value.pass.cpp
```

Author: vitalybuka

libcxx/test/std/experimental/simd/simd.reference/reference_assignment.pass.cpp

@@ -8,6 +8,9 @@
 
 // UNSUPPORTED: c++03, c++11, c++14
 
+// FIXME: Timeouts.
+// UNSUPPORTED: sanitizer-new-delete
+
 // <experimental/simd>
 //
 // [simd.reference]