Add packaging to docker (#2389)
Summary:
flash_attn requires packaging to build, so we need to include it in the docker image.
Pull Request resolved: https://github.com/pytorch/benchmark/pull/2389
Test Plan: https://github.com/pytorch/benchmark/actions/runs/10024753897
Reviewed By: manman-ren
Differential Revision: D60014445
Pulled By: xuzhao9
fbshipit-source-id: 833489011c193075ac23250383b02009b380b7f4
