Remove some now-useless unpicks (FabricMC#3882)

* Remove some now-useless unpicks

* More unpick shenanigans

Author: Shnupbups

mappings/net/minecraft/client/render/entity/model/EntityModelPartNames.mapping

@@ -158,3 +158,5 @@ CLASS net/minecraft/class_6230 net/minecraft/client/render/entity/model/EntityMo
 		COMMENT The key of a wind bottom model part, whose value is {@value}.
 	FIELD field_47450 RODS Ljava/lang/String;
 		COMMENT The key of a rods model part, whose value is {@value}.
+	FIELD field_49564 MUSHROOMS Ljava/lang/String;
+		COMMENT The key of a mushrooms model part, whose value is {@value}.

src/constants/java/net/fabricmc/yarn/constants/LlamaVariants.java

@@ -78,6 +78,7 @@ constant entity_model_parts net/minecraft/client/render/entity/model/EntityModel
 constant entity_model_parts net/minecraft/client/render/entity/model/EntityModelPartNames WIND_MID
 constant entity_model_parts net/minecraft/client/render/entity/model/EntityModelPartNames WIND_BOTTOM
 constant entity_model_parts net/minecraft/client/render/entity/model/EntityModelPartNames RODS
+constant entity_model_parts net/minecraft/client/render/entity/model/EntityModelPartNames MUSHROOMS
 constant entity_model_parts net/minecraft/client/render/entity/model/EntityModelPartNames BONE
 
 target_method net/minecraft/client/model/ModelPart getChild (Ljava/lang/String;)Lnet/minecraft/client/model/ModelPart;