Update OBJLoader.d.ts

fix #16135

examples/jsm/loaders/OBJLoader.d.ts

@@ -3,17 +3,20 @@ import {
   LoadingManager,
   Group
 } from '../../../src/Three';
+import {
+  MaterialCreator
+} from './MTLLoader';
 
 export class OBJLoader {
   constructor(manager?: LoadingManager);
   manager: LoadingManager;
   regexp: any;
-  materials: Material[];
+  materials: MaterialCreator;
   path: string;
 
   load(url: string, onLoad: (group: Group) => void, onProgress?: (event: ProgressEvent) => void, onError?: (event: ErrorEvent) => void): void;
   parse(data: string) : Group;
   setPath(value: string) : void;
-  setMaterials(materials: Material[]) : void;
+  setMaterials(materials: MaterialCreator) : void;
   _createParserState() : any;
 }