Make dropt an optional dependency

[Girouxdudes]

I understand this might be impossible, just wanted to ask on the chance that this could be done. Crafttweaker has the ability to modify block drops already, which means having both can make dropt's features feel redundant. It would be nice if there was some way to make it so that, in the presence of crafttweaker, there was no need to also have dropt installed.