Fix: revert complex conditional in Directories::contains_file

This reverts commit 6d0336b2e41703254b31f5d9a1358eb7e15cee3f.

crates/vfs/src/loader.rs

@@ -137,7 +137,10 @@ impl Directories {
     /// Returns `true` if `path` is included in `self`.
     pub fn contains_file(&self, path: &AbsPath) -> bool {
         let ext = path.extension().unwrap_or_default();
-        self.extensions.iter().any(|it| it.as_str() == ext) && self.includes_path(path)
+        if self.extensions.iter().all(|it| it.as_str() != ext) {
+            return false;
+        }
+        self.includes_path(path)
     }
 
     /// Returns `true` if `path` is included in `self`.