Fix build failure with minimal-versions

```
  error[E0432]: unresolved import `async_io::os::windows`
     --> src\reaper\wait.rs:188:27
      |
  188 |         use async_io::os::windows::Waitable;
      |                           ^^^^^^^ could not find `windows` in `os`
```

Author: taiki-e

Cargo.toml

@@ -16,7 +16,7 @@ exclude = ["/.*"]
 
 [dependencies]
 async-lock = "3.0.0"
-async-io = "2.1.0"
+async-io = "2.3.0"
 cfg-if = "1.0"
 event-listener = "5.1.0"
 futures-lite = "2.0.0"