[libc++] Remove <cstdlib> includes

We changed the `abort` calls when trying to throw exceptions in `-fno-exceptions` mode to `__verbose_abort` calls, which removes the dependency in most files.

Reviewed By: ldionne, #libc

Spies: dim, emaste, mikhail.ramalho, smeenai, libcxx-commits

Differential Revision: https://reviews.llvm.org/D146076
diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
index 75ba4b2..9970a63 100644
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -1929,6 +1929,7 @@
 #  include <atomic>
 #  include <bit>
 #  include <concepts>
+#  include <cstdlib>
 #  include <cstring>
 #  include <iterator>
 #  include <memory>