Once and for all figure out what the API status of disable torch dispatch/function is

[ezyang]

Simple functorch suggests that these are the wrong APIs https://colab.research.google.com/github/albanD/subclass_zoo/blob/main/simple_functorch.ipynb but due to how the dispatcher is implemented it is not easy to prevent people from accidentally going back to the top of the dispatch stack (incorrectly). See also https://github.com/pytorch/pytorch/issues/55093 which still should be done.