[LSan] Disable a failing test on ARM

This started failing after an OS upgrade on a buildbot machine, and I
don't see anything obvious to fix or revert, so disable it for now to
get the bot green.

Covered by https://bugs.llvm.org/show_bug.cgi?id=44158

Differential revision: https://reviews.llvm.org/D78496

compiler-rt/test/lsan/TestCases/stale_stack_leak.cpp

@@ -5,7 +5,7 @@
 // RUN: %env_lsan_opts=$LSAN_BASE":exitcode=0" %run %t 2>&1 | FileCheck --check-prefix=CHECK-sanity %s
 //
 // x86 passes parameters through stack that may lead to false negatives
-// UNSUPPORTED: x86,powerpc64
+// UNSUPPORTED: x86,powerpc64,arm
 
 #include <stdio.h>
 #include <stdlib.h>