Userland: Make Window::set_main_widget() non-fallible

Author: https://github.com/tcl3
Commit: 3aa49f268c
Pull-request: https://github.com/SerenityOS/serenity/pull/21152
Reviewed-by: https://github.com/kleinesfilmroellchen ✅

Userland/Applications/Browser/BookmarksBarWidget.cpp

@@ -53,7 +53,7 @@ private:
     BookmarkEditor(Window* parent_window, StringView title, StringView url)
         : Dialog(parent_window)
     {
-        auto widget = set_main_widget<GUI::Widget>().release_value_but_fixme_should_propagate_errors();
+        auto widget = set_main_widget<GUI::Widget>();
         widget->load_from_gml(edit_bookmark_gml).release_value_but_fixme_should_propagate_errors();
 
         set_resizable(false);