Clear counts cache when updating product attributes

Closes #17377

includes/data-stores/class-wc-product-data-store-cpt.php

@@ -696,6 +696,7 @@ class WC_Product_Data_Store_CPT extends WC_Data_Store_WP implements WC_Object_Da
 				}
 			}
 			update_post_meta( $product->get_id(), '_product_attributes', $meta_values );
+			delete_transient( 'wc_layered_nav_counts' );
 		}
 	}