[ArrayManager] TST: enable arrays tests (#40347)

Author: jorisvandenbossche

.github/workflows/ci.yml

@@ -178,6 +178,7 @@ jobs:
         pytest pandas/tests/indexing/multiindex/test_setitem.py::TestMultiIndexSetItem::test_frame_setitem_multi_column
 
         pytest pandas/tests/api/
+        pytest pandas/tests/arrays/
         pytest pandas/tests/base/
         pytest pandas/tests/computation/
         pytest pandas/tests/config/

pandas/core/internals/array_manager.py

@@ -554,7 +554,7 @@ def diff(self, n: int, axis: int) -> ArrayManager:
             # with axis=0 is equivalent
             assert n == 0
             axis = 0
-        return self.apply(algos.diff, n=n, axis=axis)
+        return self.apply(algos.diff, n=n, axis=axis, stacklevel=5)
 
     def interpolate(self, **kwargs) -> ArrayManager:
         return self.apply_with_block("interpolate", swap_axis=False, **kwargs)