Allows to revert changes applied in [54277] - temporary workaround for the failing Test NPM CI check on Windows.
Improvements included:
- generate combined asset files for both production and development
- store in the repository only the production version of the combined assets for packages, we use everything else only in development
- to make unit tests work, ensure that they ignore react fast refresh and use the production version of combined assets that are present in the source code
Props bernhard-reiter, jsnajdr, clorith, wildworks.
Fixes#56615.
Built from https://develop.svn.wordpress.org/trunk@54289
git-svn-id: http://core.svn.wordpress.org/trunk@53848 1a063a9b-81f0-0310-95a4-ce76da25c4cd
