update build.yml,use newest nix version

Author: wrjade

.github/workflows/build.yml

@@ -31,14 +31,21 @@ jobs:
     - name: Checkout
       uses: actions/checkout@v4
 
-    - name: Set up Nix with Flakes support
-      uses: cachix/install-nix-action@v22
-      with:
-        nix_path: nixpkgs=channel:nixos-unstable
-        nix_version: "3.8.5"
-        extra_nix_config: |
-          experimental-features = nix-command flakes
-          allow-import-from-derivation = true
+    - name: Install Nix 3.8.5
+      run: |
+        # 安装 Determinate Nix 3.8.5
+        curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install --version 3.8.5
+        # 重新加载环境
+        . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh
+
+    - name: Configure Nix
+      run: |
+        # 配置 Nix 以支持 Flakes
+        mkdir -p ~/.config/nix
+        cat > ~/.config/nix/nix.conf << EOF
+        experimental-features = nix-command flakes
+        allow-import-from-derivation = true
+        EOF
 
     - name: Build Docker image with Nix Flakes
       run: |