[breaking][deps] Add @babel/runtime as a peer dep

[noratarano]

Summary

Was getting the following error from another repo that didn't have it installed while I was testing version 4.0.0-alpha.1:

FAIL test/index_test.js
  ● compileCSS › returns css

    Cannot find module '@babel/runtime/helpers/interopRequireWildcard' from 'withStyles.js'

      at Resolver.resolveModule (node_modules/jest-resolve/build/index.js:221:17)
      at Object.<anonymous> (node_modules/react-with-styles/lib/withStyles.js:3:31)

We need to add it because @babel/runtime is a peer dep of babel-preset-airbnb. The reason we weren't seeing any errors for this before is because eslint-plugin-jsx-a11y (a dev dep here) had already installed it as a dependency.

Reviewers

@ljharb @lencioni @TaeKimJR @indiesquidge @ahuth @joeuy @majapw

[ljharb]

ideally the dev dep version is an exact match of the peer dep one

[noratarano]

@ljharb The issue is that eslint-plugin-jsx-a11y@6.2.3 installs 7.5.5. 🤔 so it always resolves to 7.5.5 anyway. Should we require the peer dep to be 7.5.5 or 7.0.0?

[ljharb]

Sure, but ^7 will include that too. I think ^7 is the most widely compatible.

[noratarano]

@ljharb Now the versions of @babel/runtime are set to ^7.0.0 and they match! PTAL 🙏