Chore: Update infiniteScroll type (#15794)

types/element-ui.d.ts

@@ -327,8 +327,8 @@ export class Calendar extends ElCalendar {}
 /** Backtop Component */
 export class Backtop extends ElBacktop {}
 
-/** InfiniteScroll Component */
-export class InfiniteScroll extends ElInfiniteScroll {}
+/** InfiniteScroll Directive */
+export const InfiniteScroll: PluginObject<ElInfiniteScroll>;
 
 /** PageHeader Component */
 export class PageHeader extends ElPageHeader {}

types/infiniteScroll.d.ts

 import { VNodeDirective } from 'vue'
 
-export interface ElLoadingDirective extends VNodeDirective {
+export interface ElInfiniteScroll extends VNodeDirective {
   name: 'infinite-scroll',
   value: Function
 }
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