[eslint config] [breaking] re-enable react/no-unused-prop-types

Author: ljharb

packages/eslint-config-airbnb/rules/react.js

@@ -271,7 +271,7 @@ module.exports = {
 
     // Prevent unused propType definitions
     // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/no-unused-prop-types.md
-    'react/no-unused-prop-types': ['warn', {
+    'react/no-unused-prop-types': ['error', {
       customValidators: [
       ],
       skipShapeProps: true,