Update nix requirement from 0.30.1 to 0.31.1 in /crates/cli

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@v0.30.1...v0.31.1)

---
updated-dependencies:
- dependency-name: nix
  dependency-version: 0.31.1
  dependency-type: direct:production
...

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

Author: dependabot[bot]

crates/cli/Cargo.toml

@@ -12,7 +12,7 @@ tokio = { version = "1.43", features = ["full", "rt-multi-thread"] }
 rusqlite = "0.37.0"
 regex = "1.11.1"
 indicatif = "0.18.3"
-nix = { version = "0.30.1", features = ["process"] }
+nix = { version = "0.31.1", features = ["process"] }
 serde_json = "1.0.135"
 serde = { version = "1.0", features = ["derive"] }
 libpkgx = { version = "0.7.1", path = "../lib" }