Properly use the filter for interactivity data

lib/compat/wordpress-6.5/interactivity-api/class-wp-interactivity-api.php

@@ -131,22 +131,21 @@ public function config( string $store_namespace, array $config = array() ): arra
  }
 
  /**
- * Prints the serialized client-side interactivity data.
+ * Adds interactivity data to filtered data to be passed to the client.
  *
- * Encodes the config and initial state into JSON and prints them inside a
- * script tag of type "application/json". Once in the browser, the state will
- * be parsed and used to hydrate the client-side interactivity stores and the
- * configuration will be available using a `getConfig` utility.
+ * Once in the browser, the state will be parsed and used to hydrate the client-side
+ * interactivity stores and the configuration will be available using a `getConfig` utility.
  *
  * @since 6.5.0
+ *
+ * @param array $interactivity_data Interactivity data.
+ * @return array $interactivity_data Interactivity data with store data added (if it exists).
  */
- public function print_client_interactivity_data() {
+ public function print_client_interactivity_data( $interactivity_data ) {
  if ( empty( $this->state_data ) && empty( $this->config_data ) ) {
- return;
+ return $interactivity_data;
  }
 
- $interactivity_data = array();
-
  $config = array();
  foreach ( $this->config_data as $key => $value ) {
  if ( ! empty( $value ) ) {