Attach preview apps to PRs without a comment

### Before opening, please confirm:

- [x] I have checked to see if my question is addressed in the [FAQ](https://github.com/aws-amplify/amplify-hosting/blob/master/FAQ.md).
- [x] I have [searched for duplicate or closed issues](https://github.com/aws-amplify/amplify-hosting/issues?q=is%3Aissue+).
- [x] I have removed any sensitive information from my code snippets and submission.

### Amplify Hosting feature

Deployments

### Is your feature request related to a problem? Please describe:

When Heroku deploys a [Review App](https://devcenter.heroku.com/articles/github-integration-review-apps) it attaches that as a deploy to the Pull Request e.g.


But when Amplify deploys a preview app, it attaches a comment instead:


This causes unnecessary scrolling and GitHub notifications i.e. I want to be notified once of a new PR not twice.

### Describe how you'd like this feature to work

Integrate with GitHub "releases" and attach this preview app to the PR without posting a comment.

The issue names no repository files, tests, or entry points; start by locating the existing Amplify preview-app deployment and GitHub PR comment integration. Done means the preview app is attached to the pull request through GitHub's deployment or release integration without posting a separate comment, while preserving the preview link.

Written by the indexing model from the issue text.