Remove data migration stuff that doesn't need to exist

module/documents/Actor/Mob.mjs

@@ -1 +1 @@
-export default {};
+export default {};

module/documents/Item/Handler.mjs

@@ -17,11 +17,6 @@ export class ItemHandler extends Item {
 		return this.proxyTargets[this.type];
 	};
 
-	async migrateSystemData() {
-		if (!this.fn?.migrateSystemData) return;
-		this.fn?.migrateSystemData.bind(this)();
-	};
-
 	async proxyFunction(funcName, ...args) {
 		if (!this.fn?.[funcName]) return;
 		return await this.fn?.[funcName].bind(this)(...args);

module/documents/Item/Spell.mjs

@@ -1,10 +1 @@
-import { ItemHandler } from "./Handler.mjs";
+export default {};
-
-/** @this {ItemHandler} */
-async function migrateSystemData() {
-	this.system
-};
-
-export default {
-	migrateSystemData,
-};