chore(deps): update cachix/install-nix-action action to v31

Author: renovate[bot]

.github/workflows/build.yaml

@@ -20,7 +20,7 @@ jobs:
       uses: actions/checkout@v4
 
     - name: Install Nix
-      uses: cachix/install-nix-action@v30
+      uses: cachix/install-nix-action@v31
 
     - name: Setup cachix
       uses: cachix/cachix-action@v16