Error when compiling for Redox

Just for fun, I tried to compile my program for Redox, but got this error:

```
error[E0432]: unresolved imports `rustix::fs::utimensat`, `rustix::fs::AtFlags`, `rustix::fs::UTIME_NOW`, `rustix::fs::UTIME_OMIT`
--> /home/oscar/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/fs-set-times-0.20.3/src/set_times.rs:5:20
|
5 | fs::{futimens, utimensat, AtFlags, Timestamps, CWD},
| ^^^^^^^^^ ^^^^^^^ no `AtFlags` in `fs`
| |
| no `utimensat` in `fs`
6 | fs::{UTIME_NOW, UTIME_OMIT},
| ^^^^^^^^^ ^^^^^^^^^^ no `UTIME_OMIT` in `fs`
| |
| no `UTIME_NOW` in `fs`
|
help: a similar name exists in the module
|
5 - fs::{futimens, utimensat, AtFlags, Timestamps, CWD},
5 + fs::{futimens, futimens, AtFlags, Timestamps, CWD},
|
help: a similar name exists in the module
|
5 - fs::{futimens, utimensat, AtFlags, Timestamps, CWD},
5 + fs::{futimens, utimensat, OFlags, Timestamps, CWD},
|

For more information about this error, try `rustc --explain E0432`.
error: could not compile `fs-set-times` (lib) due to 1 previous error
```

Not sure if it is s fs-set-times or a rustix issue though.

Start by reproducing the Redox compilation failure and inspect src/set_times.rs, especially its rustix filesystem imports. Determine whether the missing items require a change in fs-set-times or rustix support; done means the crate compiles successfully for Redox without the unresolved-import error.

Written by the indexing model from the issue text.