Fix new Node dialog Create button behavior

Added a one-liner to update the Create button disabled state when
selecting an item from the search results list.

Fixes #17265, long live the Realm!

(cherry picked from commit 68a4241131)

editor/create_dialog.cpp

@@ -476,6 +476,8 @@ void CreateDialog::_item_selected() {
 		return;
 
 	help_bit->set_text(EditorHelp::get_doc_data()->class_list[name].brief_description);
+
+	get_ok()->set_disabled(false);
 }
 
 void CreateDialog::_favorite_toggled() {