Remove bottlerocket/testsys cli

[ecpullen]

Issue number:

Closes #438

Description of changes:

Removes the legacy cli from the project.

Testing done:

Terms of contribution:

By submitting this pull request, I agree that this contribution is dual-licensed under the terms of both the Apache License, version 2.0, and the MIT license.

[webern]

Big 🎉

Edit: there's a thing or two to delete in the github actions configuration.

[stmcginnis]

Documentation needs to be updated to reflect this change. Most of the docs in this repo refer to using cli to do things. Before we take that away, we should have the new recommendations for what to do instead.

[ecpullen]

Documentation needs to be updated to reflect this change. Most of the docs in this repo refer to using cli to do things. Before we take that away, we should have the new recommendations for what to do instead.

cli is not being removed. The old testsys cli that hasn't been used is the one being removed. Following this pr it may be better to rename cli `testsys-cli.

Edit: I see the Quickstart guide uses the old cli. 😞

[mjsterckx]

There are references to the testsys directory/CLI in README.md, DESIGN.md, and DEVELOPER.md but I'm not sure if removing those is the responsibility of #757 or this PR (since 757 will be merged first and the testsys directory will not be removed yet at that point).

[ecpullen]

I will cover Design, readme and developer.

[stmcginnis]

Looks good, thanks!