chore(deps): bump cachix/install-nix-action from V27 to 29

Bumps [cachix/install-nix-action](https://github.com/cachix/install-nix-action) from V27 to 29. This release includes the previously tagged commit.
- [Release notes](https://github.com/cachix/install-nix-action/releases)
- [Commits](cachix/install-nix-action@V27...v29)

---
updated-dependencies:
- dependency-name: cachix/install-nix-action
  dependency-type: direct:production
...

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

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Install the Nix package manager
-        uses: cachix/install-nix-action@V27
+        uses: cachix/install-nix-action@v29
 
       - name: Flake Check
         run: nix flake check