FIX: category-selector for top level categories (#24627)

The filter for top-level categories by using parent_category_id = -1 is
only implemented by the new search API.

Follow up to commit dbb8b66a37.

app/assets/javascripts/select-kit/addon/components/category-drop.js

@@ -134,14 +134,10 @@ export default ComboBoxComponent.extend({
   ),
 
   async search(filter) {
-    const opts = {
-      parentCategoryId: this.options.parentCategory?.id || -1,
-      includeUncategorized: this.siteSettings.allow_uncategorized_topics,
-    };
-
     if (this.siteSettings.lazy_load_categories) {
       const results = await Category.asyncSearch(filter, {
-        ...opts,
+        parentCategoryId: this.options.parentCategory?.id || -1,
+        includeUncategorized: this.siteSettings.allow_uncategorized_topics,
         limit: 15,
       });
       return this.shortcuts.concat(
@@ -157,6 +153,10 @@ export default ComboBoxComponent.extend({
       );
     }
 
+    const opts = {
+      parentCategoryId: this.options.parentCategory?.id,
+    };
+
     if (filter) {
       let results = Category.search(filter, opts);
       return this._filterUncategorized(results).sort((a, b) => {