type_info: avoid testing constexpr-ness because older compilers don't guarantee it

test/entt/core/type_info.cpp

@@ -54,7 +54,7 @@ TEST(TypeInfo, Functionalities) {
     ASSERT_EQ(entt::type_id<int &>(), entt::type_id<int &&>());
     ASSERT_EQ(entt::type_id<int &>(), entt::type_id<int>());
 
-    constexpr auto info = entt::type_id<int>();
+    auto info = entt::type_id<int>();
     const auto unnamed = entt::type_id<float>();
     entt::type_info empty{};