LibWeb: Incorrectly skip visiting MessagePort::m_worker_event_target

This is a stopgap hack to prevent CI from hanging until we figure out
what's going on.

Bug: https://github.com/SerenityOS/serenity/issues/23899

Userland/Libraries/LibWeb/HTML/MessagePort.cpp

@@ -52,6 +52,10 @@ void MessagePort::visit_edges(Cell::Visitor& visitor)
 {
     Base::visit_edges(visitor);
     visitor.visit(m_remote_port);
+
+    // FIXME: This is incorrect!! We *should* be visiting the worker event target,
+    //        but CI hangs if we do: https://github.com/SerenityOS/serenity/issues/23899
+    visitor.ignore(m_worker_event_target);
 }
 
 void MessagePort::set_worker_event_target(JS::NonnullGCPtr<DOM::EventTarget> target)