feat: 新增GitHub Actions工作流以同步到CNB.cool

- 创建sync-to-cnb.yaml工作流文件
- 配置在推送时自动同步代码到CNB.cool仓库
- 使用Docker容器执行同步操作，确保环境一致性

Signed-off-by: longjin <longjin@DragonOS.org>

Author: fslongjin

.github/workflows/sync-to-cnb.yaml

@@ -0,0 +1,23 @@
+name: Sync to CNB.cool
+on: [push]
+
+jobs:
+  sync:
+    if: github.repository == 'DragonOS-Community/ci-dashboard'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+      
+      - name: Sync to CNB Repository
+        run: |
+          docker run --rm \
+            -v ${{ github.workspace }}:${{ github.workspace }} \
+            -w ${{ github.workspace }} \
+            -e PLUGIN_TARGET_URL="https://cnb.cool/DragonOS-Community/ci-dashboard.git" \
+            -e PLUGIN_AUTH_TYPE="https" \
+            -e PLUGIN_USERNAME="cnb" \
+            -e PLUGIN_PASSWORD=${{ secrets.CNB_GIT_PASSWORD }} \
+            -e PLUGIN_FORCE="true" \
+            tencentcom/git-sync