chore(deps): bump nix from 0.30.1 to 0.31.2

Bumps [nix](https://github.com/nix-rust/nix) from 0.30.1 to 0.31.2.
- [Changelog](https://github.com/nix-rust/nix/blob/master/CHANGELOG.md)
- [Commits](nix-rust/nix@v0.30.1...v0.31.2)

---
updated-dependencies:
- dependency-name: nix
  dependency-version: 0.31.2
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]