fix: convert old usage of close btn to the new one

npm/ng-packs/packages/theme-basic/src/lib/components/page-alert-container/page-alert-container.component.html

@@ -11,12 +11,10 @@
     <button
       *ngIf="alert.dismissible"
       type="button"
-      class="close"
+      class="btn-close"
       data-dismiss="alert"
       aria-label="Close"
       (click)="service.remove(i)"
-    >
-      <span aria-hidden="true">&times;</span>
-    </button>
+    ></button>
   </div>
 </ng-container>

npm/ng-packs/packages/theme-shared/src/lib/components/http-error-wrapper/http-error-wrapper.component.html

@@ -8,11 +8,9 @@
     *ngIf="!hideCloseIcon"
     id="abp-close-button"
     type="button"
-    class="close me-2"
+    class="btn-close me-2"
     (click)="destroy()"
-  >
-    <span aria-hidden="true">&times;</span>
-  </button>
+  ></button>
 
   <div *ngIf="!customComponent" class="row centered">
     <div class="col-md-12">