chore: updatae docstring for consistency

tests/utils/test_defence.py

@@ -338,7 +338,7 @@ class Test_IsExpectedFiletype(object):
     """Tests for _is_expected_filetype."""
 
     def test_is_expected_filetype_raises_single(self):
-        """Test when `exp_ext` is a single string."""
+        """Test raises when `exp_ext` is a single string."""
         with pytest.raises(
             ValueError,
             match="`raster` expected file extension .gif. Found .tiff",