tweak

Author: lemire

cppcon2025/cppcon_2025_slides.md

@@ -308,7 +308,7 @@ let player: Player = serde_json::from_str(&json_str)?;
 | Go       |       ✅            |       ❌                |
 | Java     |       ✅            |       ❌                |
 | C#       |       ✅            |       ❌                |
-| Rust     |       ❌ (macros)   |       ❌                |
+| Rust     |       ❌            |       ❌   (macros)     |
 
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