The policy says "We ask that you accurately tag your project if it contains materials produced by generative AI by utilizing the AI Disclosure section on your project’s edit page.".
Why would that not apply to code bundled with your project?
Viewing post in Generative AI Disclosure tagging
Because you could unbundle it and have the user get the runtime distribution files for the engine, library or whatever dependencies it has.
Look here for an explanation https://www.rpgmakerweb.com/run-time-package
More commonly known and seen might be the requirement for your system to install Visual C++ Redistributeables, if you install certain games.
What about browser games? If it only runs in Chrome, it will make use of ai code. If you bundle your game with Chrome, your project's files will have ai code. But would anyone consider the project itself to be in any way ai made?
That the policy and implementation could be better, goes without saying. I prefer the disclosure as seen on Steam. It is details in text.
But even there, I have doubts that you would see a disclosure about how the engine used would have some ai code in it. As I said, Chrome contains ai code. Every web game that only runs bug free on Chrome, or is even bundled with a Chromium, would fall under the code ai section, if you would apply the ai question transitive.
This is not the intent of the ai disclosure. Leafo made a statement about this somewhere here. The opinion was, you should only tag a dependency that has ai in it, if you chose that dependency because it has ai in it. It follows, if you merely chose that dependency, because that library is a common library, or happens to be your game engine, or bundled browser, that the disclosure questions do not apply. It's about the things put into the game, not the things necessary to run the game.