(MOB): Correct eslint use of cache

Correction following this correction on react-scripts facebook/create-react-app#9911 (merged)
Cache location inspired of what will certainly will be in react-scrips facebook/create-react-app#9977 (not merged at this time)
   but it doesn't really matter

config/webpack.config.js

@@ -667,6 +667,8 @@ module.exports = function (webpackEnv) {
  formatter: require.resolve('react-dev-utils/eslintFormatter'),
  eslintPath: require.resolve('eslint'),
  context: paths.appSrc,
+ cache: true,
+ cacheLocation: path.resolve(paths.appNodeModules, '.cache', '.eslintcache'),
  // ESLint class options
  cwd: paths.appPath,
  resolvePluginsRelativeTo: __dirname,