fix(ci): add git token to update secrets repo

.forgejo/workflows/cachix.yml

@@ -14,14 +14,21 @@ jobs:
 
     - name: Setup-Nix
       uses: https://github.com/cachix/install-nix-action@v24
-    - uses: https://github.com/yaxitech/nix-install-pkgs-action@v3
+
+    - name: Install-nixci
+      uses: https://github.com/yaxitech/nix-install-pkgs-action@v3
       with:
         packages: "nixpkgs#nixci"
-    - uses: https://github.com/cachix/cachix-action@v12
+
+    - name: Setup-cachix
+      uses: https://github.com/cachix/cachix-action@v12
       with:
         name: archives
         authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
 
-    - name: Build configs
+    - name: Build-configs
       run: |
+        eval `ssh-agent -s`
+        ssh-add - <<< '${{ secrets.PRIVATE_SSH_KEY }}'
+        nix flake update
         nixci