Bumps [cachix/install-nix-action](https://github.com/cachix/install-nix-action) from 31.5.2 to 31.6.0.
- [Release notes](https://github.com/cachix/install-nix-action/releases)
- [Changelog](https://github.com/cachix/install-nix-action/blob/master/RELEASE.md)
- [Commits](fc6e360bed...56a7bb7b56)
---
updated-dependencies:
- dependency-name: cachix/install-nix-action
dependency-version: 31.6.0
dependency-type: direct:production
update-type: version-update:semver-minor
...
Signed-off-by: dependabot[bot] <support@github.com>