Don't use externalised babel helpers (#108)

* Don't use externalised babel helpers

* npm version 1.3.1

---------

Co-authored-by: jeff-horton-ho-sas <jeff-horton-ho-sas@users.noreply.github.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@ukhomeoffice/react-components",
-  "version": "1.3.0",
+  "version": "1.3.1",
   "description": "React components for Home Office layouts and elements",
   "main": "dist/ho-react-components.js",
   "module": "dist/ho-react-components.module.js",
@@ -9,7 +9,7 @@
     "pretest:unit-built": "npm run build",
     "test": "npm run test:unit",
     "lint": "eslint . --ext jsx,js",
-    "test:unit": "npm run test:unit-source",
+    "test:unit": "npm run test:unit-source && npm run test:unit-built",
     "test:unit-built": "jest --config scripts/jest/config.build.mjs",
     "test:unit-source": "jest --config scripts/jest/config.source.mjs",
     "test:watch": "npm run test:unit-source -- --watch",
@@ -41,7 +41,6 @@
   "devDependencies": {
     "@babel/core": "^7.26.0",
     "@babel/eslint-plugin": "^7.25.9",
-    "@babel/plugin-external-helpers": "^7.25.9",
     "@babel/plugin-transform-runtime": "^7.25.9",
     "@babel/preset-env": "^7.26.0",
     "@babel/preset-react": "^7.26.3",

rollup.config.js

@@ -49,8 +49,7 @@ export default {
         }),
         babel({
             exclude: 'node_modules/**',
-            plugins: ['@babel/plugin-external-helpers'],
-            babelHelpers: 'external',
+            babelHelpers: 'bundled',
         }),
         terser({
             sourceMap: true