LibWeb: Add missing edge visit for TextTrack in HTMLTrackElement

Userland/Libraries/LibWeb/HTML/HTMLTrackElement.h

@@ -25,6 +25,7 @@ private:
     HTMLTrackElement(DOM::Document&, DOM::QualifiedName);
 
     virtual void initialize(JS::Realm&) override;
+    virtual void visit_edges(Cell::Visitor&) override;
 
     // ^DOM::Element
     virtual void attribute_changed(FlyString const& name, Optional<String> const& value) override;