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/Libraries/LibGUI/CommandPalette.cpp

@@ -183,7 +183,7 @@ CommandPalette::CommandPalette(GUI::Window& parent_window, ScreenPosition screen
 
     collect_actions(parent_window);
 
-    auto main_widget = set_main_widget<GUI::Frame>().release_value_but_fixme_should_propagate_errors();
+    auto main_widget = set_main_widget<GUI::Frame>();
     main_widget->set_frame_style(Gfx::FrameStyle::Window);
     main_widget->set_fill_with_background_color(true);