format && add nix-serve for caching

.gitea/workflows/deploy.yaml

@@ -12,6 +12,10 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
       - uses: cachix/install-nix-action@v31
+        with:
+          extra_nix_config: |
+            extra-trusted-public-keys = localhost:TiRpr2LzamX/MCKBUmFlZ8inWz94QWGL88fMEHg9Kgc=
+            extra-substituters = http://localhost:5000
       - uses: actions/checkout@v4
       - name: Install SSH key
         uses: shimataro/ssh-key-action@v2