Refactor build workflow to copy .next directory

Remove rsync command and copy .next directory directly.

Author: xc2f

.github/workflows/build-to-branch.yml

@@ -66,7 +66,9 @@ jobs:
           git config user.email "github-actions@github.com"
 
           # 拷贝 .next 但排除 cache
-          rsync -av --exclude='cache' .next/ /tmp/next-build
+          # rsync -av --exclude='cache' .next/ /tmp/next-build
+          rm -rf .next/cache
+          cp -r .next /tmp/next-build
 
           # 切换或创建 build 分支
           git checkout -B build