ices/65159.rs: fixed with errors

[github-actions]

Issue: rust-lang/rust#65159

=== stdout ===
=== stderr ===
error[E0670]: `async fn` is not permitted in the 2015 edition
 --> /home/runner/work/glacier/glacier/ices/65159.rs:1:1
  |
1 | async fn copy() -> Result<()>
  | ^^^^^

error[E0107]: wrong number of type arguments: expected 2, found 1
 --> /home/runner/work/glacier/glacier/ices/65159.rs:1:20
  |
1 | async fn copy() -> Result<()>
  |                    ^^^^^^^^^^ expected 2 type arguments

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0107, E0670.
For more information about an error, try `rustc --explain E0107`.
==============