ci(publish): Update runner and build target for Linux deployment

- Change runner from windows-latest to ubuntu-latest for cross-platform compatibility
- Update build command from pnpm build:win to pnpm build:linux
- Disable Windows code signing configuration as no longer needed
- Align CI/CD pipeline with Linux-based deployment requirements

.gitea/workflows/publish.yml

@@ -12,7 +12,7 @@ concurrency:
 
 jobs:
   publish:
-    runs-on: windows-latest
+    runs-on: ubuntu-latest
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
@@ -65,7 +65,7 @@ jobs:
 
       - name: Build for Windows
         run: |
-          pnpm build:win
+          pnpm build:linux
         env:
           # 禁用 Windows 代码签名
           WIN_CSC_KEY_PASSWORD: ''