add numpy typing plugin to mypy config (#92930)
This added the numpy typing plugin to mypy config so that we could
use it for DeviceMesh typing annotations
Please see https://github.com/pytorch/pytorch/pull/92931 about why we need this. For example, we are currently saving the DeviceMesh's mesh field as torch.Tensor, where when we do sth like:
```python
with FakeTensorMode():
device_mesh = DeviceMesh("cuda", torch.arange(4))
```
It would throw error because FakeTensorMode or any TorchDispatchMode tracks every tensor creation and interactions. While DeviceMesh just want to save a nd-array to record the mesh topology, and would like to avoid the interaction with subsystems like FakeTensor, so we want to support saving `mesh` as numpy array instead.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/92930
Approved by: https://github.com/ezyang, https://github.com/malfet
