Examples are broken on macOS when compiling with nightly

[polina4096]

Examples fail to compile when following the procedure stated in the README on macOS (Apple Silicon) with nightly rustc.

error[E0308]: mismatched types
  --> /Users/polina4096/.cargo/registry/src/index.crates.io-6f17d22bba15001f/accesskit_macos-0.10.1/src/patch.rs:44:13
   |
44 |             focus_forwarder as unsafe extern "C" fn(_, _) -> _,
   |             ^^^^^^^^^^^^^^^ one type is more general than the other
   |
   = note: expected fn pointer `unsafe extern "C" fn(&NSWindow, objc2::runtime::Sel) -> _`
              found fn pointer `unsafe extern "C" for<'a> fn(&'a NSWindow, objc2::runtime::Sel) -> _`