pytorch

fe8bfef8 - Extract setting up ec2 linux and checkout to be composite actions (#80462)

Extract setting up ec2 linux and checkout to be composite actions (#80462) Step 1 to gradually change our generated workflow scripts to be more compatible with reusable workflows. This PR extracts three pieces of functionality into composite actions: - Checking out the branch - Setting up EC2 linux - Building the linux binary It also regenerates the workflows to use these new composite actions This is not a complete list of things we'd like to extract. Keeping this PR small to get early feedback Pull Request resolved: https://github.com/pytorch/pytorch/pull/80462 Approved by: https://github.com/seemethere