cleanup unused code and mixins

src/main/java/carpet/mixins/GuardianEntityMixin.java

@@ -10,7 +10,6 @@ import net.minecraft.entity.mob.GuardianEntity;
 import net.minecraft.entity.mob.HostileEntity;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.server.world.ServerWorld;
-import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.World;
 import org.spongepowered.asm.mixin.Mixin;