Actually skip test_std

Author: honno

Diff for: array_api_tests/test_statistical_functions.py

@@ -187,6 +187,7 @@ def test_prod(x, data):
         ph.assert_scalar_equals("prod", type_=scalar_type, idx=out_idx, out=prod, expected=expected)
 
 
+@pytest.mark.skip(reason="flaky")  # TODO: fix!
 @given(
     x=hh.arrays(
         dtype=xps.floating_dtypes(),