Add tools/ script to limit circleci to a set of jobs (#58001)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58001
Adds a script so that devs can generate a commit (at the base of a stack) that removes all CI jobs but the set that they care about. See CONTRIBUTING.md changes for usage
Test Plan: Imported from OSS
Reviewed By: mruberry
Differential Revision: D28359910
Pulled By: driazati
fbshipit-source-id: 2741570f2bab2c28f4a9d7aef727b1b2399d0ce1
