servo: Merge #19709 - style: Remove -servo-display-for-hypothetical-box from longhand (from CYBAI:servo-display-out-of-mako); r=emilio

This is a sub-PR of #19015
r? emilio

For the `fn set_original_display` inside `properties.mako.rs`, I removed `is_item_or_root` first to see how the tests result is. If it's needed, I'll add it back.

---
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #19697
- [x] These changes do not require tests

Source-Repo: https://github.com/servo/servo
Source-Revision: 1b46e2e7597e90a41c6bfb3bd7008bdd922c93c6

servo/components/layout/construct.rs

@@ -1485,7 +1485,7 @@ impl<'a, ConcreteThreadSafeLayoutNode> PostorderNodeMutTraversal<ConcreteThreadS
             }
             Some(LayoutNodeType::Element(_)) => {
                 let style = node.style(self.style_context());
-                let original_display = style.get_box()._servo_display_for_hypothetical_box;
+                let original_display = style.get_box().original_display;
                 let munged_display = match original_display {
                     Display::Inline | Display::InlineBlock => original_display,
                     _ => style.get_box().display,