chore: upgrade to webpack encore 7

webpack.config.mjs

@@ -0,0 +1,37 @@
+import Encore from '@symfony/webpack-encore';
+
+if (!Encore.isRuntimeEnvironmentConfigured()) {
+    Encore.configureRuntimeEnvironment(process.env.NODE_ENV || 'dev');
+}
+
+Encore
+    .setOutputPath('public/build/')
+    .setPublicPath('/build')
+    .addEntry('app', './assets/app.js')
+    .addEntry('admin', './assets/admin.js')
+    .splitEntryChunks()
+
+    // enables the Symfony UX Stimulus bridge (used in assets/bootstrap.js)
+    .enableStimulusBridge('./assets/controllers.json')
+    .enableSingleRuntimeChunk()
+    .cleanupOutputBeforeBuild()
+    .enableSourceMaps(!Encore.isProduction())
+    .enableVersioning(Encore.isProduction())
+    // Babel 8 dropped preset-env's useBuiltIns/corejs; polyfill-corejs3 is its replacement
+    .configureBabel((babelConfig) => {
+        babelConfig.plugins.push(['polyfill-corejs3', {method: 'usage-global', version: '3.23'}]);
+    })
+    // Encore 7 ships no CSS minifier of its own
+    .configureCssMinimizerPlugin((options, MinimizerPlugin) => {
+        options.minify = MinimizerPlugin.lightningCssMinify;
+    })
+    .enablePostCssLoader()
+    .copyFiles([
+        {from: './assets/images', to: 'images/[path][name].[hash:8].[ext]'},
+        {from: './assets/favicon', to: 'favicon/[path][name].[hash:8].[ext]'},
+        // voucher thumbnails
+        {from: './assets/vouchers', to: 'images/vouchers/[path][name].[hash:8].[ext]', pattern: /\.jpg$/},
+    ])
+;
+
+export default await Encore.getWebpackConfig();