fix: make ItemModel#Builder#guiLight mutable

Author: radstevee

gradle.properties

@@ -5,4 +5,4 @@ org.jetbrains.dokka.experimental.gradle.pluginMode.noWarn=true
 org.gradle.caching=true
 org.gradle.parallel=true
 
-packedVersion=1.0.1
+packedVersion=1.0.2

packed-core/src/main/kotlin/net/radstevee/packed/core/item/ItemModel.kt

@@ -107,7 +107,7 @@ public class ItemModel private constructor(
         public var parent: String? = null
         public var display: ItemModelDisplay? = null
         public var textures: MutableMap<String, Key>? = null
-        public val guiLight: String? = null
+        public var guiLight: String? = null
         public var cubes: MutableList<Cube>? = null
         public var overrides: MutableList<OverrideCase>? = null