chore(deps): update cachix/cachix-action action to v14 (#108)

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This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [cachix/cachix-action](https://togithub.com/cachix/cachix-action) |
action | major | `v13` -> `v14` |

---

### Release Notes

<details>
<summary>cachix/cachix-action (cachix/cachix-action)</summary>

### [`v14`](https://togithub.com/cachix/cachix-action/releases/tag/v14):
cachix-action-v14

[Compare
Source](https://togithub.com/cachix/cachix-action/compare/v13...v14)

https://blog.cachix.org/posts/2024-01-12-cachix-v1-7/

</details>

---

### Configuration

📅 **Schedule**: Branch creation - "every weekend" (UTC), Automerge - At
any time (no schedule defined).

🚦 **Automerge**: Enabled.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the
rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update
again.

---

- [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check
this box

---

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.github/workflows/check.yml

@@ -21,7 +21,7 @@ jobs:
     steps:
       - name: Install Nix
         uses: cachix/install-nix-action@v25
-      - uses: cachix/cachix-action@v13
+      - uses: cachix/cachix-action@v14
         with:
           name: nixpkgs-ruby
           authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'