Add cached conda env file for Buck CI workflow (#89422)
Fixes - T137631262
Caching conda dependencies for build workflows.
Conda dependencies have been gathered from the workflow https://github.com/pytorch/pytorch/blob/master/.github/workflows/_buck-build-test.yml
The pull request updates the action from `conda-incubator/setup-miniconda@v2` to `pytorch/test-infra/.github/actions/setup-miniconda@main` as it supports caching.
Test Plan:
Running the `ciflow/periodic` which runs the ci builds `buck-build-test` workflow. Expected output is to have all the conda dependencies cached.
<img width="1227" alt="Screenshot 2022-11-22 at 15 44 20" src="https://user-images.githubusercontent.com/15447437/203343298-e55c384b-01ad-45c3-a5e9-ba5c53149be4.png">
Pull Request resolved: https://github.com/pytorch/pytorch/pull/89422
Approved by: https://github.com/huydhn
