Load unminified JS when SCRIPT_DEBUG is true.

[noahtallen]

Description

Resolves #23960. (Though, I wonder if this will not be possible because of #32621.)

When SCRIPT_DEBUG is true, load index.js build files instead of index.min.js build files.

Testing Instructions

Locally, in wp-env, SCRIPT_DEBUG is true by default. If you have no other overrides, you should see non-minified files in the debug devtools tab when loading the editor.

Then, add this to .wp-env.json or .wp-env.override.json:

	"config": {
		"SCRIPT_DEBUG": false
	}

Then, when loading the editor, you'll see minified files in the debug devtools tab:

Screenshots

Minified files:

Unminified files:

Types of changes

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• I've tested my changes with keyboard and screen readers.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR (please manually search all *.native.js files for terms that need renaming or removal).
• I've updated related schemas if appropriate.

[youknowriad]

When running npm run dev we only generate .min.js files, though in reality it's a non minified file. Should we update the npm run dev build step to also include .js files? maybe we can just avoid breakage in this case and always load the non minified versions.