update ci

.forgejo/workflows/deploy.yaml

@@ -11,12 +11,13 @@ jobs:
 
       - name: Setup Nix
         uses: https://github.com/cachix/install-nix-action@v27
+        with:
+          nix_path: nixpkgs=channel:nixpkgs-unstable
 
       - name: Build Docs
         run: |
-          nix develop
           nix build .#md-manual --out-link docs
-          mkdocs build -d ./public
+          nix-shell -p 'python312.withPackages(ps: with ps; [ mkdocs-material mkdocs pillow cairosvg ])' --run "mkdocs build -d ./public"
 
       - name: Deploy
         uses: https://git.pyrox.dev/actions/pages-action@v2