[ci]在工作流配置中添加手动触发功能，允许通过`workflow_dispatch`手动启动同步任务。

.github/workflows/sync-demo-0.x.yml

@@ -3,12 +3,12 @@
 name: SYNC DEMO 0.x
 
 on:
+    workflow_dispatch:
     push:
         branches:
             - 0.x
         paths:
             - 'demo/**'
-
 jobs:
     sync:
         runs-on: ubuntu-latest