Sort imports of test_datapipe.py (#61312)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/61312
Sorting according to isort output. Alphabetically ordered one per line imports help merging.
Test Plan: Imported from OSS
Reviewed By: ejguan
Differential Revision: D29588833
Pulled By: VitalyFedyunin
fbshipit-source-id: 4c80c3086132b50894e734ad6c5799d78d689e42
