Refactor prefetch_project_files function for improved readability

- Simplified the iteration over directory entries in the `prefetch_project_files` function by using `into_iter().flatten()` instead of a nested loop.
- This change enhances code clarity while maintaining the existing functionality of collecting valid directory entries.

These modifications aim to streamline the code and improve maintainability in the prefetching process.

src/serve_session.rs

@@ -152,10 +152,8 @@ fn prefetch_project_files(project: &Project) -> io::Result<PrefetchCache> {
         if !root.exists() {
             continue;
         }
-        for entry in WalkDir::new(root).follow_links(true) {
-            if let Ok(e) = entry {
-                entries.push(e);
-            }
+        for e in WalkDir::new(root).follow_links(true).into_iter().flatten() {
+            entries.push(e);
         }
     }