Fix torch import causing release build failure

[mrwyattii]

The torch import added in #4452 causes an ImportError when trying to build a release for DeepSpeed in environments without torch:

Traceback (most recent call last):
  File "setup.py", line 37, in <module>
    from op_builder import get_default_compute_capabilities, OpBuilder
  File "/home/runner/work/DeepSpeed/DeepSpeed/op_builder/__init__.py", line 48, in <module>
    module = importlib.import_module(f".{module_name}", package=op_builder_dir)
  File "/usr/lib/python3.8/importlib/__init__.py", line [12](https://github.com/microsoft/DeepSpeed/actions/runs/6436848308/job/17481015251#step:6:13)7, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "/home/runner/work/DeepSpeed/DeepSpeed/op_builder/async_io.py", line 8, in <module>
    import torch
ModuleNotFoundError: No module named 'torch'

@jeffra
@loadams

[lynquantumman]

deepspeed-0.13.0 still has this problem

[loadams]

Hi @lynquantumman - thanks for letting us know, this is covered/tracked in more detail here, we are working to fix this, thanks!