fix: mark react-redux package as a peer dependency

[vivek1729]

• I have read the Contributor Guide
• I have updated the changelogs/current_changelog.md file with some information about the change that I am making the appropriate file.
• I have validated or unit-tested the changes that I have made.
• I have run through the TEST_PLAN.md to ensure that my change does not break anything else.

A recent Pull request bumped up the mono repo to leverage react-redux v7 😃 . This is awesome as it sets us up to take several advantages of new apis. In that change, I noticed that react-redux was marked as a peer dependency as well as a regular dependency for some nested packages. Specifically:

• myths
• notebook-app-component
• connected-components
• stateful-components

While, it makes sense to manage react-redux as a regular dependency at the top level or for the individual applications, we'd want to ship nested nteract packages like myths etc to claim this package as a peer dependency only. This allows the users to manage a single copy of these core modules (like they already do for react right now).

[vercel]

This pull request is being automatically deployed with Vercel (learn more).
To see the status of your deployment, click below or on the icon next to each commit.

🔍 Inspect: https://vercel.com/nteract/site/9oH9wcWDfusaFyzBBZPXBQvWmKqG
✅ Preview: https://site-git-fork-vivek1729-vipradha-reactreduxpeerdep-nteract.vercel.app

[MSeal]

I'd consider also moving redux to the peerDependencies section. Thoughts @captainsafia ?