Bump nix from 0.15.0 to 0.16.0

Bumps [nix](https://github.com/nix-rust/nix) from 0.15.0 to 0.16.0.
- [Release notes](https://github.com/nix-rust/nix/releases)
- [Changelog](https://github.com/nix-rust/nix/blob/master/CHANGELOG.md)
- [Commits](https://github.com/nix-rust/nix/commits/v0.16.0)

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

Author: dependabot-preview[bot]

src/minion/Cargo.toml

@@ -13,7 +13,7 @@ serde = { version = "1.0.103", features = ["derive"] }
 serde_json = "1.0.42"
 tiny-nix-ipc = { git = "https://github.com/myfreeweb/tiny-nix-ipc", features = ["ser_json", "zero_copy"] }
 procfs = "0.7.4"
-nix = "0.15.0"
+nix = "0.16.0"
 downcast-rs = "1.1.1"
 snafu = "0.6.0"
 base64 = "0.11.0"