LibWeb: Add missing base class upcalls in Node::inserted() overrides

Author: https://github.com/awesomekling
Commit: 003c045589
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3345
Reviewed-by: https://github.com/AtkinsSJ

Libraries/LibWeb/HTML/HTMLProgressElement.cpp

@@ -92,6 +92,7 @@ double HTMLProgressElement::position() const
 
 void HTMLProgressElement::inserted()
 {
+    Base::inserted();
     create_shadow_tree_if_needed();
 }