fix: fix for pull request finding 'Empty except'

Co-authored-by: Copilot Autofix powered by AI <223894421+github-code-quality[bot]@users.noreply.github.com>

Author: ChenZiHong-Gavin

graphgen/operators/read/parallel_file_scanner.py

@@ -194,8 +194,8 @@ def _cache_result(self, key: str, result: Dict, path: Path):
                 },
             )
             logger.info("[READ] Cached scan result for path: %s", path)
-        except OSError:
-            pass
+        except OSError as e:
+            logger.error("[READ] Failed to cache scan result for path %s: %s", path, e)
 
     def _is_allowed_file(self, path: Path) -> bool:
         """Check if the file has an allowed suffix"""