fix: course-04/exercises/lesson-5/client/package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-LODASH-6139239

Author: snyk-bot

course-04/exercises/lesson-5/client/package.json

@@ -11,7 +11,7 @@
     "react": "^16.8.6",
     "react-dom": "^16.8.6",
     "react-router-dom": "^5.0.1",
-    "react-scripts": "2.1.8",
+    "react-scripts": "4.0.0",
     "semantic-ui-css": "^2.4.1",
     "semantic-ui-react": "^0.86.0",
     "styled-components": "^4.3.2",