LibWeb: Make factory method of HTML::SubmitEvent fallible

Author: https://github.com/kennethmyhra
Commit: 809206f50e
Pull-request: https://github.com/SerenityOS/serenity/pull/17491
Reviewed-by: https://github.com/linusg ✅

Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp

@@ -83,7 +83,7 @@ void HTMLFormElement::submit_form(JS::GCPtr<HTMLElement> submitter, bool from_su
 
         SubmitEventInit event_init {};
         event_init.submitter = submitter_button;
-        auto submit_event = SubmitEvent::create(realm(), EventNames::submit, event_init);
+        auto submit_event = SubmitEvent::create(realm(), EventNames::submit, event_init).release_value_but_fixme_should_propagate_errors();
         submit_event->set_bubbles(true);
         submit_event->set_cancelable(true);
         bool continue_ = dispatch_event(*submit_event);