chore: phpstan fix

Author: HardeepAsrani

classes/Visualizer/Module/Setup.php

@@ -472,7 +472,7 @@ public function custom_cron_schedules( $schedules ) {
 	/**
 	 * Schedule the recurring DB refresh action.
 	 */
-	private function schedule_refresh_db_action() {
+	private function schedule_refresh_db_action(): void {
 		$hook         = 'visualizer_schedule_refresh_db';
 		$group        = 'visualizer';
 		$interval_key = apply_filters( 'visualizer_chart_schedule_interval', 'visualizer_ten_minutes' );
@@ -495,7 +495,7 @@ private function schedule_refresh_db_action() {
 	/**
 	 * Unschedule the recurring DB refresh action.
 	 */
-	private function unschedule_refresh_db_action() {
+	private function unschedule_refresh_db_action(): void {
 		$hook  = 'visualizer_schedule_refresh_db';
 		$group = 'visualizer';
 		if ( function_exists( 'as_unschedule_all_actions' ) ) {

classes/Visualizer/Module/Upgrade.php

@@ -83,7 +83,7 @@ private static function makeAllTableChartsTabular() {
 	/**
 	 * Migrate recurring WP-Cron jobs to Action Scheduler.
 	 */
-	private static function migrate_action_scheduler() {
+	private static function migrate_action_scheduler(): void {
 		if ( ! function_exists( 'as_schedule_recurring_action' ) || ! function_exists( 'as_next_scheduled_action' ) ) {
 			return;
 		}