build(deps): bump cachix/install-nix-action in the actions group (#272)

Bumps the actions group with 1 update: [cachix/install-nix-action](https://github.com/cachix/install-nix-action).


Updates `cachix/install-nix-action` from V28 to 29
- [Release notes](https://github.com/cachix/install-nix-action/releases)
- [Commits](cachix/install-nix-action@V28...v29)

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

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

@@ -23,7 +23,7 @@ jobs:
           submodules: true
       # - run: sudo apt-get update && sudo apt-get install -y qemu-user-static
       - name: Setup Nix
-        uses: cachix/install-nix-action@V28
+        uses: cachix/install-nix-action@v29
         with:
           # newer versions result in different store paths
           install_url: https://releases.nixos.org/nix/nix-2.18.5/install