make callback optional

Author: MrSpoocy

src/utils.ts

@@ -1,6 +1,6 @@
 import * as CSInterface from "./v9";
 
-export function evalScript(script: string, callback: (result?: any) => void): Promise<any> {
+export function evalScript(script: string, callback?: (result?: any) => void): Promise<any> {
     /**
      *
      * @param {*} value

src/v8.ts

@@ -515,7 +515,7 @@ export default class CSInterface {
      * @param callback  Optional. A callback function that receives the result of execution.
      *          If execution fails, the callback function receives the error message EvalScript_ErrMessage.
      */
-    evalScript(script: string, callback: (result?: any) => void | null): void {
+    evalScript(script: string, callback?: (result?: any) => void | null): void {
         if (callback === null || callback === undefined) {
             callback = function (result) {
             };