Pin ShellCheck version to v0.7.1 (#55109)
Summary:
Not sure why I didn't do this in https://github.com/pytorch/pytorch/issues/47786. Version 0.7.1 (the latest `"stable"` version of ShellCheck) was released [almost a year ago](https://github.com/koalaman/shellcheck/releases/tag/v0.7.1), but even if releases are infrequent, it's better to just get rid of the nondeterminism that caused https://github.com/pytorch/pytorch/issues/47786 in the first place.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/55109
Test Plan: The "Lint / quick-checks" job in GitHub Actions.
Reviewed By: janeyx99
Differential Revision: D27483473
Pulled By: samestep
fbshipit-source-id: e09f52844db440f2b6ea3cd54340c9e62dea09f4
