fix return value structure

Author: Leon-hk

src/gardenlinux/features/reproducibility/comparator.py

@@ -145,7 +145,7 @@ def generate(self, a: PathLike[str], b: PathLike[str]) -> tuple[list[Path], bool
         """
 
         if filecmp.cmp(a, b):
-            return []
+            return [], False
 
         with self._unpack(a) as unpacked_a, self._unpack(b) as unpacked_b:
             cmp = filecmp.dircmp(unpacked_a, unpacked_b, shallow=False)