fix: narrow exception catch in filepath encode to (FileNotFoundError, OSError)

Addresses review comment — the bare `except Exception` was too broad.
backend.size() can only fail with filesystem-related errors.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: dimitri-yatsenko

src/datajoint/builtin_codecs/filepath.py

@@ -153,7 +153,7 @@ def encode(self, value: Any, *, key: dict | None = None, store_name: str | None
         if not is_dir:
             try:
                 size = backend.size(path)
-            except Exception:
+            except (FileNotFoundError, OSError):
                 pass
 
         return {