add missing includes to fix layering check (#1347)

Signed-off-by: Luca Della Vedova <lucadv@intrinsic.ai>

src/entt/entity/snapshot.hpp

@@ -3,6 +3,7 @@
 
 #include "../config/config.h"
 #include "../container/dense_map.hpp"
+#include "../core/type_info.hpp"
 #include "../core/type_traits.hpp"
 #include "../stl/concepts.hpp"
 #include "../stl/cstddef.hpp"

src/entt/meta/template.hpp

@@ -4,6 +4,7 @@
 #define ENTT_META_TEMPLATE_HPP
 
 #include "../core/type_traits.hpp"
+#include "type_traits.hpp"
 
 namespace entt {