[ci-change] add LTS branch auto build

**Phenomenon and reproduction steps**

none

**Root cause and solution**

none

**Impactions**

none

**Test method**

none

**Affected branch(es)**

- main
- v6.3

**Checklist**

- [ ] Dependencies update required
- [ ] Common bug (similar problem in other repo)

Author: twou12031

.github/workflows/main.yml

@@ -8,6 +8,7 @@ on:
   push:
     branches:
       - main
+      - 'v**'
       - 'feature-**'
       - latest
       - backend-plugin