change 'children' to const

Author: orukusaki

app/code/Magento/PageBuilder/view/adminhtml/web/ts/js/stage-builder.ts

@@ -245,7 +245,7 @@ function createInitialElementData(fields: ConfigFieldInterface): FieldDefaultsIn
  */
 function getElementChildren(element: HTMLElement): HTMLElement[] {
     if (element.hasChildNodes()) {
-        let children: any[] = [];
+        const children: any[] = [];
         // Find direct children of the element
         _.forEach(element.childNodes, (child: HTMLElement) => {
             if (child.nodeType === Node.ELEMENT_NODE) {