[Project] Improve release workflow

[kmcginnes]

The release workflow has a few steps that can be automated using GitHub Actions.

A typical release follows these steps:

1. Create & merge a PR with updated versions & changelog
2. Create branch for version & smoke test
3. Create release in GitHub
4. Run ECR image workflow for release

If we treat creating the release in GitHub as a trigger, we can automate the following:

• Create branch from release
• Run ECR image workflow for release