Bump cachix/cachix-action from 12 to 13 (#14)

Bumps [cachix/cachix-action](https://github.com/cachix/cachix-action) from 12 to 13.
- [Release notes](https://github.com/cachix/cachix-action/releases)
- [Commits](cachix/cachix-action@v12...v13)

---
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/build.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Install Nix
         uses: DeterminateSystems/nix-installer-action@v8
       - name: Setup Cachix
-        uses: cachix/cachix-action@v12
+        uses: cachix/cachix-action@v13
         with:
           name: nixpkgs-terraform
           authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}