Use GitHub's diff directly in clang-tidy (#60048)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/60048
This changes clang-tidy in lint.yml to pull the raw diff from GitHub and parse that rather than use the PRs base revision. The base revision can cause the spurious inclusion of files not changed in the PR as in https://github.com/pytorch/pytorch/pull/59967/checks?check_run_id=2832565901. We could be smarter about how we query git, but this approach ends up being simpler since we just need to search for the diff headers in the .diff file.
See https://github.com/pytorch/pytorch/pull/60049/checks?check_run_id=2834140350 for an example CI run with this on
Test Plan: Imported from OSS
Reviewed By: samestep
Differential Revision: D29148886
Pulled By: driazati
fbshipit-source-id: ca23446d5cc8938d1345f272afe77b9ee8898b74
