Revert "add APIs to determine a class is a namedtuple or PyStructSequence (#113257)"

Summary:
This reverts commit f08146b67bab331f7bdc9fa247f526f6e60a7190.

Reverted pytorch/pytorch#113257 on behalf of https://github.com/jovianjaison due to breaking internal builds ([comment](pytorch/pytorch#113257 (comment)))

Differential Revision: D70903497

fbshipit-source-id: 8e6cc0702ff8498c4a6a5e6623a9cdd188e063c7

Author: generatedunixname499836121

userbenchmark/dynamo/dynamobench/common.py

@@ -1419,7 +1419,7 @@ def load(cls, model, example_inputs):
                 # see https://github.com/pytorch/pytorch/issues/113029
                 example_outputs = copy.deepcopy(model)(*example_args, **example_kwargs)
 
-            if pytree.is_namedtuple_instance(example_outputs):
+            if pytree._is_namedtuple_instance(example_outputs):
                 typ = type(example_outputs)
                 pytree._register_namedtuple(
                     typ,