Upgrade Storybook to 8.4

[jattasNI]

Pull Request

🤨 Rationale

I saw that Storybook released a new minor version which is supposed to have a bunch of improvements. An exciting sounding one: "We cut bundle size in half" though the package-lock has about as many additions as subtractions

👩‍💻 Implementation

Followed their docs which basically involved:

1. Run npx storybook@latest upgrade
2. Agree to the prompts to auto-update stuff
3. The tool also suggested we might be able to remove our React dependency but I didn't try this because I know we create some custom React components so it seems correct for us to depend on it

🧪 Testing

1. Manually inspected our stories including the ones that use custom React components
2. verified Chromatic did a full rebuild, no turbosnaps, and there are no diffs

✅ Checklist

• I have updated the project documentation to reflect my changes or determined no changes are needed.