Make lintrunner compatible with M1 (#78628)
numpy-1.20 is not available on the platform, so change pinned version to 1.21.6
Pull Request resolved: https://github.com/pytorch/pytorch/pull/78628
Approved by: https://github.com/suo, https://github.com/ZainRizvi, https://github.com/janeyx99, https://github.com/seemethere
