refactor(config): remove stencil extras (#26461)

BREAKING CHANGE:

The supported version of Firefox for Ionic v7 has changed to Firefox v70+

core/scripts/cdn-loader.js

@@ -1,30 +0,0 @@
-
-exports.applyPolyfills = function() { return Promise.resolve() };
-
-exports.defineCustomElements = function(_, opts) {
-  return new Promise(function(resolve, reject) {
-    if (typeof document !== 'undefined') {
-      opts = opts || {};
-      var mod = document.createElement('script');
-      mod.setAttribute('type', 'module');
-      mod['data-opts'] = opts;
-      mod.src = '__CDN_LOADER_URL__/dist/ionic/ionic.esm.js';
-
-      var legacy = document.createElement('script');
-      legacy.setAttribute('nomodule', '');
-      legacy['data-opts'] = opts;
-      legacy.src = '__CDN_LOADER_URL__/dist/ionic/ionic.js';
-
-      mod.onload = resolve;
-      mod.onerror = reject;
-
-      legacy.onload = resolve;
-      legacy.onerror = reject;
-
-      document.head.appendChild(mod);
-      document.head.appendChild(legacy);
-    } else {
-      resolve();
-    }
-  });
-}

core/scripts/copy-cdn-loader.js

@@ -1,28 +0,0 @@
-
-// the unpkg link cannot use "latest" in the url
-// so this script is to keep the link updated
-// with the latest
-
-const fs = require('fs');
-const path = require('path');
-
-let version = process.argv[2];
-
-if (version) {
-  version = '@' + version;
-} else {
-  version = '';
-}
-
-const srcPath = path.join(__dirname, 'cdn-loader.js');
-let scriptContent = fs.readFileSync(srcPath, 'utf-8');
-
-// https://unpkg.com/@ionic/core@latest/dist/ionic.js
-
-scriptContent = scriptContent.replace(
-  /__CDN_LOADER_URL__/g,
-  'https://cdn.jsdelivr.net/npm/@ionic/core' + version
-);
-
-fs.writeFileSync(path.join(__dirname, '..', 'loader', 'cdn.js'), scriptContent);
-fs.writeFileSync(path.join(__dirname, '..', 'loader', 'index.cjs.js'), scriptContent);