Add peer dependency for react-csv

[ryankshaw]

react-csv uses propTypes in its runtime code

What's the problem this PR addresses?

this makes it so consumers of react-csv don't have to add this to their package.json

    "packageExtensions": {
      "react-csv": {
        "dependencies": {
          "prop-types": "*"
        }
      }
    },

...

How did you fix it?

by sending a PR upstream and contributing your extension to the @yarnpkg/extensions database, like this recommends

...

Checklist

• I have read the Contributing Guide.

• I have set the packages that need to be released for my changes to be effective.

• I will check that all automated PR checks pass before the PR gets reviewed.