LibWeb+Assistant: Do not ref-capture stack vars in deferred lambdas

Author: https://github.com/mattco98
Commit: 31c5cdcbd5
Pull-request: https://github.com/SerenityOS/serenity/pull/23876
Issue: https://github.com/SerenityOS/serenity/issues/23791
Reviewed-by: https://github.com/awesomekling

Userland/Applications/Assistant/main.cpp

@@ -258,7 +258,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
         }
 
         mark_selected_item();
-        Core::deferred_invoke([&] { window->resize(GUI::Desktop::the().rect().width() / 3, {}); });
+        Core::deferred_invoke([window] { window->resize(GUI::Desktop::the().rect().width() / 3, {}); });
     }));
 
     db.on_new_results = [&](auto results) {

Userland/Libraries/LibWeb/Layout/BlockFormattingContext.cpp

@@ -664,7 +664,7 @@ void BlockFormattingContext::layout_block_level_box(Box const& box, BlockContain
                 m_margin_state.reset();
             } else if (!m_margin_state.has_block_container_waiting_for_final_y_position()) {
                 // margin-top of block container can be updated during children layout hence it's final y position yet to be determined
-                m_margin_state.register_block_container_y_position_update_callback([&](CSSPixels margin_top) {
+                m_margin_state.register_block_container_y_position_update_callback([&, introduce_clearance](CSSPixels margin_top) {
                     if (introduce_clearance == DidIntroduceClearance::No) {
                         place_block_level_element_in_normal_flow_vertically(box, margin_top + y);
                     }