LibWeb: Delete unused m_animation_driver_timer in Document

Author: https://github.com/kalenikaliaksandr
Commit: 9a5ef95022
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/5476
Reviewed-by: https://github.com/gmta ✅

Libraries/LibWeb/DOM/Document.cpp

@@ -4445,9 +4445,6 @@ void Document::did_stop_being_active_document_in_navigable()
     notify_each_document_observer([&](auto const& document_observer) {
         return document_observer.document_became_inactive();
     });
-
-    if (m_animation_driver_timer)
-        m_animation_driver_timer->stop();
 }
 
 void Document::increment_throw_on_dynamic_markup_insertion_counter(Badge<HTML::HTMLParser>)

Libraries/LibWeb/DOM/Document.h

@@ -1170,7 +1170,6 @@ private:
 
     // https://www.w3.org/TR/web-animations-1/#pending-animation-event-queue
     Vector<PendingAnimationEvent> m_pending_animation_event_queue;
-    RefPtr<Core::Timer> m_animation_driver_timer;
 
     // https://drafts.csswg.org/css-transitions-2/#current-transition-generation
     size_t m_transition_generation { 0 };