LibWeb: Propagate more StringBuilder errors in from StyleValues

Userland/Libraries/LibWeb/CSS/StyleValue.cpp

@@ -1476,12 +1476,12 @@ ErrorOr<String> GridTemplateAreaStyleValue::to_string() const
     StringBuilder builder;
     for (size_t y = 0; y < m_grid_template_area.size(); ++y) {
         for (size_t x = 0; x < m_grid_template_area[y].size(); ++x) {
-            builder.appendff("{}", m_grid_template_area[y][x]);
+            TRY(builder.try_appendff("{}", m_grid_template_area[y][x]));
             if (x < m_grid_template_area[y].size() - 1)
-                builder.append(" "sv);
+                TRY(builder.try_append(" "sv));
         }
         if (y < m_grid_template_area.size() - 1)
-            builder.append(", "sv);
+            TRY(builder.try_append(", "sv));
     }
     return builder.to_string();
 }