chore(deps): update cachix/install-nix-action digest to 2126ae7 (#267)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/nix.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       # Install Nix on the runner
-      - uses: cachix/install-nix-action@4e002c8ec80594ecd40e759629461e26c8abed15  # v31
+      - uses: cachix/install-nix-action@2126ae7fc54c9df00dd18f7f18754393182c73cd  # v31
         with:
           nix_path: nixpkgs=channel:nixos-unstable
       # Pull from the cachix cache