Update Rust crate nix to 0.30 (#8419)

Author: oxide-renovate[bot]

Cargo.lock

@@ -542,7 +542,7 @@ nexus-test-interface = { path = "nexus/test-interface" }
 nexus-test-utils-macros = { path = "nexus/test-utils-macros" }
 nexus-test-utils = { path = "nexus/test-utils" }
 nexus-types = { path = "nexus/types" }
-nix = { version = "0.29", features = ["net"] }
+nix = { version = "0.30", features = ["net"] }
 nom = "7.1.3"
 num-integer = "0.1.46"
 num = { version = "0.4.3", default-features = false, features = [ "libm" ] }