Build Tools:

- Update the DependencyExtractionWebpackPlugin to 2.3.0 and set it to output a single assets file.
- Grunt: copy the assets file to both `SOURCE_DIR` and `BUILD_DIR` as `wp-includes/assets/script-loader-packages.php`.
- "Unignore" the `wp-includes/assets` directory. Its content will be committed similarly to `wp-includes/blocks`.
- Update `wp_default_packages_scripts()` to use the above file. This also removes the hard-coded lists of packages and packages with translations.

Props gziolo, pbearne, johnbillion, isabel_brison, ocean90, azaozz.
Fixes #48154.

git-svn-id: https://develop.svn.wordpress.org/trunk@47352 602fd350-edb4-49c9-b593-d223f7449a82

tools/webpack/packages.js

@@ -246,6 +246,7 @@ module.exports = function( env = { environment: 'production', watch: false, buil
 			} ),
 			new DependencyExtractionPlugin( {
 				injectPolyfill: true,
+				combineAssets: true,
 			} ),
 			new CopyWebpackPlugin(
 				[