Re-add an `ArchetypeComponentId` parallel schedule executor

> I think this is a better default, and it unlocks a lot of functionality. As we clean up the executor code, we should re-add a archetype-parallel executor for people to compare against.

_Originally posted by @alice-i-cecile in https://github.com/bevyengine/bevy/issues/16885#issuecomment-2852559534_


Most real Bevy apps appear overparallelized at present, and will benefit from the lower overhead, but not all apps will always be like that. We should just be able to create an alternate executor that users can toggle.