build(deps): update nix requirement from 0.29 to 0.30

Updates the requirements on [nix](https://github.com/nix-rust/nix) to permit the latest version.
- [Changelog](https://github.com/nix-rust/nix/blob/master/CHANGELOG.md)
- [Commits](nix-rust/nix@v0.29.0...v0.30.1)

---
updated-dependencies:
- dependency-name: nix
  dependency-version: 0.30.1
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Cargo.toml

@@ -31,7 +31,7 @@ crossbeam = "0.8.1"
 futures = "0.3.19"
 libc = "0.2.112"
 log = {version = "0.4.2", features=["kv_unstable"]}
-nix = "0.29"
+nix = "0.30"
 oci-spec = "0.7"
 os_pipe = "1.1"
 prctl = "1.0.0"