PHP 8.4.1 Deprecation notice: WP_Rocket\Engine\Common\Queue\RUCSSQueueRunner::__construct(): Implicitly marking parameter $store as nullable is deprecated, the explicit nullable type must be used instead

[alfonso100]

Describe the bug
A customer using PHP 8.4.1 reported the following Deprecation notices:

Deprecated WP_Rocket\Engine\Common\Queue\RUCSSQueueRunner::__construct(): Implicitly marking parameter $async_request as nullable is deprecated, the explicit nullable type must be used instead
wp-content/plugins/wp-rocket/inc/Engine/Common/Queue/RUCSSQueueRunner.php:63
Composer\Autoload\includeFile()
/var/www/html/waf/vendor/composer/ClassLoader.php:322
Composer\Autoload\ClassLoader->loadClass()
wp-content/plugins/wp-rocket/inc/Engine/Common/JobManager/Cron/Subscriber.php:93
WP_Rocket\E\C\J\C\Subscriber->initialize_rucss_queue_runner()
wp-includes/class-wp-hook.php:324
do_action('init')
wp-settings.php:704

To Reproduce
Steps to reproduce the behavior:

1. Update to PHP 8.4.1
2. See the deprecation notice

Expected behavior
We should update the code to prevent the deprecation notice
according to @wordpressfan :

That's a valid point that needs github issue, that deprecation was explained here: https://php.watch/versions/8.4/implicitly-marking-parameter-type-nullable-deprecated we just need to add ? here:

wp-rocket/inc/Engine/Common/Queue/RUCSSQueueRunner.php

Line 63 in 7348869

public function __construct( \ActionScheduler_Store $store = null, \ActionScheduler_FatalErrorMonitor $monitor = null, Cleaner $cleaner = null, \ActionScheduler_AsyncRequest_QueueRunner $async_request = null ) {

to be

public function __construct( ?\ActionScheduler_Store $store = null, \ActionScheduler_FatalErrorMonitor $monitor = null, Cleaner $cleaner = null, \ActionScheduler_AsyncRequest_QueueRunner $async_request = null ) {

Additional context
Ticket: https://secure.helpscout.net/conversation/2813601201/533978?viewId=2683093
Slack Thread: https://wp-media.slack.com/archives/C43T1AYMQ/p1736350050088929