Update nix requirement from 0.27 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@v0.27.0...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

@@ -12,12 +12,12 @@ readme = "README.md"
 bitflags = "2.4.0"
 cfg-if = "^1.0.0"
 libc = "0.2.65"
-nix = { version = "0.27", features = ["ioctl"] }
+nix = { version = "0.30", features = ["ioctl"] }
 thiserror = "1.0.4"
 userfaultfd-sys = { path = "userfaultfd-sys", version = "^0.6.0" }
 
 [dev-dependencies]
-nix = { version = "0.27", features = ["poll", "mman", "feature"] }
+nix = { version = "0.30", features = ["poll", "mman", "feature"] }
 
 [features]
 default = []