Remove eager mode support form CommTensor (#84978)
We don't need eager mode support (automatic wait on read) for now.
Removing that to simply the code. We can always add this back if
necessary in the future.
Note that, we still need the eager mode code in `__torch_dispatch__`,
as `make_fx` will also run the ops in eager mode to get the output.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/84978
Approved by: https://github.com/wanchaol
