Fix target-specific feature flags for rustix dependency (#96)

The "rustix::process" module is only imported for
`cfg(target_os = "linux")`, but the "process" feature of rustix was
only enabled if the target_os was *not* "linux".

This change enables the "process" feature on unix-y platforms
in general, which should be more robust.

Author: decathorpe

Cargo.toml

@@ -24,15 +24,12 @@ tracing = { version = "0.1.40", default-features = false }
 
 [target.'cfg(unix)'.dependencies]
 async-signal = "0.2.3"
-rustix = { version = "1.0", default-features = false, features = ["std", "fs"] }
+rustix = { version = "1.0", default-features = false, features = ["std", "fs", "process"] }
 
 [target.'cfg(any(windows, target_os = "linux"))'.dependencies]
 async-channel = "2.0.0"
 async-task = "4.7.0"
 
-[target.'cfg(all(unix, not(target_os = "linux")))'.dependencies]
-rustix = { version = "1.0", default-features = false, features = ["std", "fs", "process"] }
-
 [target.'cfg(windows)'.dependencies]
 blocking = "1.0.0"