fix: remove unneeded persist

tldraw/packages/core/src/lib/TLApp/TLApp.ts

@@ -399,7 +399,6 @@ export class TLApp<
 
   @action addAssets<T extends TLAsset>(assets: T[]): this {
     assets.forEach(asset => (this.assets[asset.id] = asset))
-    this.persist()
     return this
   }