dependabot: bump nix from 0.27.1 to 0.29.0

Bumps [nix](https://github.com/nix-rust/nix) from 0.27.1 to 0.29.0.
- [Changelog](https://github.com/nix-rust/nix/blob/master/CHANGELOG.md)
- [Commits](nix-rust/nix@v0.27.1...v0.29.0)

---
updated-dependencies:
- dependency-name: nix
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Cargo.toml

@@ -65,7 +65,7 @@ memoffset = "0.9.1"
 min-max = "0.1.8"
 more-asserts = "0.3.1"
 mut_static = "5.0.0"
-nix = "0.27.1"
+nix = "0.29.0"
 numtoa = "0.2.4"
 # TODO: instead of `once_cell` crate, use `std::sync::OnceLock` when it becomes stable
 #       TRACKING: https://github.com/rust-lang/rust/issues/74465