fix(curriculum): use cdnjs instead of unpkg (freeCodeCamp#60286)

Author: ojeytonwilliams

curriculum/challenges/english/25-front-end-development/lab-color-picker/67bf4350777ac6ffdc027745.md

@@ -170,9 +170,9 @@ async () => {
     <meta charset="UTF-8" />
     <title>Color Picker</title>
     <link rel="stylesheet" href="styles.css" />
-    <script src="https://unpkg.com/react@18/umd/react.development.js"></script>
-    <script src="https://unpkg.com/react-dom@18/umd/react-dom.development.js"></script>
-    <script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/react/18.3.1/umd/react.development.min.js"></script>
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/18.3.1/umd/react-dom.development.min.js"></script>
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/babel-standalone/7.26.5/babel.min.js"></script>
     <script
       data-plugins="transform-modules-umd"
       type="text/babel"

tools/client-plugins/browser-scripts/webpack.config.cjs

@@ -92,7 +92,7 @@ module.exports = (env = {}) => {
     },
     // To keep the client React version decoupled from the curriculum React
     // version we use externals to stops Webpack from bundling React and
-    // ReactDOM (they're fetched from unpkg when needed by the client or
+    // ReactDOM (they're fetched from the cdn when needed by the client or
     // curriculum tests). react-dom/server and react-dom/test-utils are included
     // separately because enzyme-adapter-react-16 imports them directly.
     externals: {