Fix: Categories Block: hierarchical Dropdown (#13567)

Previously higher than second levels categories here rendered multiple times on the categories block, when "Show Hierarchy" and "Display as Dropdown" options here true.
This commit fixes that problem.

packages/block-library/src/categories/edit.js

@@ -106,7 +106,8 @@ class CategoriesEdit extends Component {
 	}
 
 	renderCategoryDropdown() {
-		const { showHierarchy, instanceId } = this.props;
+		const { instanceId } = this.props;
+		const { showHierarchy } = this.props.attributes;
 		const parentId = showHierarchy ? 0 : null;
 		const categories = this.getCategories( parentId );
 		const selectId = `blocks-category-select-${ instanceId }`;