Draft PRs don't trigger Chromatic build

[craigpalermo]

Describe the bug
Draft PRs don't trigger the Chromatic merge check. This feature is useful when devs want to get feedback on WIP changes, but can confuse reviewers if a change isn't actually ready for review.

Affected project(s) (e.g. pcln-design-system, pcln-modal, etc.)
n/a

To Reproduce
Steps to reproduce the behavior:

1. Open a draft PR

Expected behavior
Draft PRs should run Chromatic build step to generate a static storybook

Screenshots