changed require to dynamic imports

In the previous state, the code presents the following error when the gulp command is ran: Error [ERR_REQUIRE_ESM]: require() of ES Module /.../node-test/node_modules/gulp-autoprefixer/index.js from /.../node-test/gulpfile.js not supported.
Instead change the require of index.js in /.../node-test/gulpfile.js to a dynamic import() which is available in all CommonJS modules.
    at Object.<anonymous> (/.../node-test/gulpfile.js:3:22) {
  code: 'ERR_REQUIRE_ESM'
}

files/en-us/learn/tools_and_testing/cross_browser_testing/automated_testing/index.md

@@ -172,7 +172,7 @@ To use each plugin, you need to first install it via npm, then require any depen
 2. Add the following dependency to `gulpfile.js`:
 
    ```js
-   const htmltidy = require("gulp-htmltidy");
+   import htmltidy from "gulp-htmltidy";
    ```
 
 3. Add the following test to the bottom of `gulpfile.js`:
@@ -216,8 +216,8 @@ In the input version of the file, you may have noticed that we put an empty {{ht
 2. Add the following dependencies to `gulpfile.js`:
 
    ```js
-   const autoprefixer = require("gulp-autoprefixer");
-   const csslint = require("gulp-csslint");
+   import autoprefixer from "gulp-autoprefixer";
+   import csslint from "gulp-csslint";
    ```
 
 3. Add the following test to the bottom of `gulpfile.js`:
@@ -245,19 +245,13 @@ In the input version of the file, you may have noticed that we put an empty {{ht
    ]
    ```
 
-5. Add this line after the const definitions:
-
-   ```js
-   const { series } = require("gulp");
-   ```
-
-6. Export the css task using:
+5. Export the css task using:
 
    ```js
    exports.css = css;
    ```
 
-7. Change the default task to:
+6. Change the default task to:
 
    ```js
    exports.default = series(html, css);
@@ -278,8 +272,8 @@ Here we grab our `style.css` file, run csslint on it (which outputs a list of an
 2. Add the following dependencies to `gulpfile.js`:
 
    ```js
-   const babel = require("gulp-babel");
-   const jshint = require("gulp-jshint");
+   import babel from "gulp-babel";
+   import jshint from "gulp-jshint"
    ```
 
 3. Add the following test to the bottom of `gulpfile.js`: