unused import [4/n] (#3414)

Summary:
X-link: facebookresearch/dlrm#406

Pull Request resolved: #3414

https://www.flake8rules.com/rules/F401.html

Reviewed By: TroyGarden

Differential Revision: D83739270

fbshipit-source-id: c07b33d779fe52135890f06efca800e3851d08db

Author: aliafzal

torchrec/distributed/benchmark/benchmark_zch/data/get_dataloader.py

@@ -9,8 +9,6 @@
 import argparse
 import os
 
-from typing import Union
-
 import yaml
 from torch.utils.data import DataLoader
 

torchrec/distributed/planner/tests/test_partitioners.py

@@ -7,7 +7,6 @@
 
 # pyre-strict
 
-import copy
 import unittest
 from typing import cast, List
 from unittest.mock import MagicMock