ices/78459.rs: fixed with no errors

[github-actions]

Issue: rust-lang/rust#78459

#![feature(allocator_api)]

fn main() {
    Box::new_in(&[0, 1], &std::alloc::Global);
}

=== stdout ===
=== stderr ===
warning: unused return value of `Box::<T, A>::new_in` that must be used
 --> /home/runner/work/glacier/glacier/ices/78459.rs:4:5
  |
4 |     Box::new_in(&[0, 1], &std::alloc::Global);
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `#[warn(unused_must_use)]` on by default

warning: 1 warning emitted

==============