chore(deps): update cachix/install-nix-action digest to ab73962

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@616559265b40713947b9c190a8ff4b507b5df49b  # v31
+      - uses: cachix/install-nix-action@ab739621df7a23f52766f9ccc97f38da6b7af14f  # v31
         with:
           nix_path: nixpkgs=channel:nixos-unstable
       # Pull from our cachix cache (currently unused)