build(deps): bump cachix/install-nix-action from 31.6.0 to 31.6.1

Bumps [cachix/install-nix-action](https://github.com/cachix/install-nix-action) from 31.6.0 to 31.6.1.
- [Release notes](https://github.com/cachix/install-nix-action/releases)
- [Changelog](https://github.com/cachix/install-nix-action/blob/master/RELEASE.md)
- [Commits](56a7bb7b56...7be5dee142)

---
updated-dependencies:
- dependency-name: cachix/install-nix-action
  dependency-version: 31.6.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

.github/workflows/nix.yml

@@ -42,7 +42,7 @@ jobs:
             /nix
             /zig
       - name: Setup Nix
-        uses: cachix/install-nix-action@56a7bb7b56d9a92d4fd1bc05758de7eea4a370a8 # v31.6.0
+        uses: cachix/install-nix-action@7be5dee1421f63d07e71ce6e0a9f8a4b07c2a487 # v31.6.1
         with:
           nix_path: nixpkgs=channel:nixos-unstable
       - uses: cachix/cachix-action@0fc020193b5a1fa3ac4575aa3a7d3aa6a35435ad # v16