Hey makvo, unfortunately a 1.18 update can not happen. I've already explained why so I will copy paste the response I gave on my discord server below. If you have any specific questions about what I say feel free to reach out over discord:
https://discord.gg/H32FcPp
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"There is no solution to the problem. FarmCraft only supports 1.17 because the 1.18 spigot update took away proper developer access to NMS. Basically NMS is like the actual minecraft code rather than the Spigot code. Spigot said that you should never need to use NMS because Spigot can do everything minecraft can do, but that's a lie. I physically cannot support the textured heads in 1.18 because Spigot broke that functionality intentionally."