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

Author: renovate[bot]

.github/actions/install-nix/action.yml

@@ -14,6 +14,6 @@ runs:
 
     - name: Install Nix ❄️
       if: ${{ steps.check-nix.outputs.nix-found != 'true' }}
-      uses: cachix/install-nix-action@v30
+      uses: cachix/install-nix-action@v31
       with:
         github_access_token: ${{ github.token }}