Bump cachix/cachix-action from 13 to 14 (#179)

Bumps [cachix/cachix-action](https://github.com/cachix/cachix-action) from 13 to 14.
- [Release notes](https://github.com/cachix/cachix-action/releases)
- [Commits](cachix/cachix-action@v13...v14)

---
updated-dependencies:
- dependency-name: cachix/cachix-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/nix.yml

@@ -23,7 +23,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: cachix/install-nix-action@v25
       - name: Setup Cachix
-        uses: cachix/cachix-action@v13
+        uses: cachix/cachix-action@v14
         with:
           name: saber
           authToken: "${{ secrets.CACHIX_AUTH_TOKEN }}"