[jit] test_complexity.py - don't set default dtype in global scope (#106486)
Summary:
Depending on import order, this was sometimes causing another assert to fail:
https://github.com/pytorch/pytorch/blob/aec8418bd951a9ed3d4835596d11b8365a44dfa3/torch/testing/_internal/jit_metaprogramming_utils.py#L20
Differential Revision: D48011132
Pull Request resolved: https://github.com/pytorch/pytorch/pull/106486
Approved by: https://github.com/eellison
