print logs of ephemeral instance after executing preview-cmd

[lukqw]

Background

With @remotesynth and @HarshCasper working on the blog post for ephemeral instances and application previews, they have identified the need for getting logs of LocalStack, in case the deployment of their application (= preview-cmd) failed. Debugging issues with a deployment on LocalStack without logs is basically impossible.

Solution

This PR invokes the new endpoint to fetch logs of ephemeral instances after the preview-cmd is finished, and prints them.

[github-actions[bot]]

The ephemeral instance for the application preview has been shut down