registry: thanks MSVC for accepting invalid C++ code

src/entt/entity/registry.hpp

@@ -304,7 +304,7 @@ class basic_registry {
         auto &cpool = pools[id];
 
         if(!cpool) {
-            using alloc_type = storage_for_type<std::remove_const_t<Type>>::allocator_type;
+            using alloc_type = typename storage_for_type<std::remove_const_t<Type>>::allocator_type;
 
             if constexpr(std::is_same_v<Type, void> && !std::is_constructible_v<alloc_type, allocator_type>) {
                 // std::allocator<void> has no cross constructors (waiting for C++20)