Ignore missing_abi lint in nightly-2025-01-16

    warning: extern declarations without an explicit ABI are deprecated
       --> tests/test_ensure.rs:617:43
        |
    617 |     let test = || Ok(ensure!(extern_fn as extern fn() as usize * 0 != 0));
        |                                           ^^^^^^ help: explicitly specify the C ABI: `extern "C"`
        |
        = note: `#[warn(missing_abi)]` on by default

Author: dtolnay

tests/test_ensure.rs

@@ -614,6 +614,7 @@ fn test_as() {
 
     extern "C" fn extern_fn() {}
     #[rustfmt::skip]
+    #[allow(missing_abi)]
     let test = || Ok(ensure!(extern_fn as extern fn() as usize * 0 != 0));
     assert_err(
         test,