MAINT: fix typo in test_array_object test description (#22071)

Original NumPy Commit: 7c8e1134ae86f8a8c002e1068337bec63ddf7f0d

Author: Ikko Ashimine

array_api_strict/tests/test_array_object.py

@@ -364,7 +364,7 @@ def test_array_keys_use_private_array():
     in __getitem__(). This is achieved by passing array_api arrays with 0-sized
     dimensions, which NumPy-proper treats erroneously - not sure why!
 
-    TODO: Find and use appropiate __setitem__() case.
+    TODO: Find and use appropriate __setitem__() case.
     """
     a = ones((0, 0), dtype=bool_)
     assert a[a].shape == (0,)