Libraries: Use default constructors/destructors in LibWeb

https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#cother-other-default-operation-rules

"The compiler is more likely to get the default semantics right and
you cannot implement these functions better than the compiler."

Userland/Libraries/LibWeb/Layout/TableRowBox.cpp

@@ -19,8 +19,6 @@ TableRowBox::TableRowBox(DOM::Document& document, DOM::Element* element, CSS::Co
 {
 }
 
-TableRowBox::~TableRowBox()
-{
-}
+TableRowBox::~TableRowBox() = default;
 
 }