fix(surround): remove all posible dupplicate paths

Author: farnabaz

src/runtime/internal/surround.ts

@@ -17,10 +17,10 @@ export async function generateItemSurround<T extends PageCollectionItemBase>(que
   ] as ContentNavigationItem[]
 }
 
-function flattedData(data: ContentNavigationItem[]) {
+export function flattedData(data: ContentNavigationItem[]) {
   const flatData = data.flatMap((item) => {
     const children: ContentNavigationItem[] = item.children ? flattedData(item.children) : []
-    if (item.page === false || (children.length && children[0].path === item.path)) {
+    if (item.page === false || (children.length && children.find(c => c.path === item.path))) {
       return children
     }