build(deps): update nix requirement from 0.27 to 0.28

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...v0.28.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

apps/Cargo.toml

@@ -30,7 +30,7 @@ octets = { version = "0.2", path = "../octets" }
 ring = "0.16"
 quiche = { path = "../quiche" }
 libc = "0.2"
-nix = { version = "0.27", features = ["net", "socket", "uio"] }
+nix = { version = "0.28", features = ["net", "socket", "uio"] }
 
 [lib]
 crate-type = ["lib"]