removed special.zeta grad

Author: Chillee

test/functorch_lagging_op_db.py

@@ -482,7 +482,6 @@
     ('special.polygamma', 'special_polygamma_n_0'),
     ('special.xlog1py', ''),
     ('special.zeta', ''),
-    ('special.zeta', 'grad'),
     ('split', ''),
     ('split', 'list_args'),
     ('split_with_sizes', ''),

test/test_pythonkey.py

@@ -358,7 +358,6 @@ class TestEagerFusionOpInfo(TestCase):
         skip('msort'),
         xfail('nn.functional.dropout'),
         xfail('polar'),
-        xfail('special.zeta', 'grad'),
         xfail('to_sparse'),
         xfail('addcdiv'),
         xfail('cholesky'),