Run lintrunner on CI (#266)

Summary:
There are a bunch of flake8 errors which I'll fix in a different PR and land them together to avoid complicating this one

### Testing

https://github.com/pytorch/executorch/actions/runs/6152384722

Pull Request resolved: https://github.com/pytorch/executorch/pull/266

Reviewed By: larryliu0820

Differential Revision: D49168984

Pulled By: huydhn

fbshipit-source-id: 91788ca6cefe457ddfe5c81521ca094ac62ef9e6