ci: feature `asm_experimental_arch` is declared but not used

```log error: feature `asm_experimental_arch` is declared but not used --> src/lib.rs:117:44 | 117 | #![cfg_attr(asm_experimental_arch, feature(asm_experimental_arch))] | ^^^^^^^^^^^^^^^^^^^^^ | = note: `-D unused-features` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(unused_features)]` error: could not compile `rustix` (lib test) due to 1 previous error ```