fix: modern yarn install production command fails

[WataruNishimura]

First of all, I am Japanese so my English may be incorrect.

Description of changes

I have fixed the issue below. https://github.com/aws-amplify/amplify-cli/issues/13377

This issue is caused by install command without devDependencies changes after major version 2 in yarn.

Specifically, yarn install --production changed deprecated and yarn workspaces focus --all --production is recommended. This is described by below Yarn official website. https://yarnpkg.com/cli/workspaces/focus

The new command also needs @yarnpkg/plugin-workspace-tools. I wrote the code confirm the plugin is installed and works.

Issue #, if available

#13377

Description of how you validated changes

I wrote the test that checks workspace plugin is installed as unit test.

Checklist

• [x] PR description included
• [x] yarn test passes
• [x] Tests are changed or added

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.