build: remove entt library

include/entt/core/family.hpp

@@ -1,35 +0,0 @@
-#ifndef ENTT_CORE_FAMILY_HPP
-#define ENTT_CORE_FAMILY_HPP
-
-#include "../config/config.h"
-#include "fwd.hpp"
-
-namespace entt {
-
-/**
- * @brief Dynamic identifier generator.
- *
- * Utility class template that can be used to assign unique identifiers to types
- * at runtime. Use different specializations to create separate sets of
- * identifiers.
- */
-template<typename...>
-class family {
-    static auto identifier() noexcept {
-        static ENTT_MAYBE_ATOMIC(id_type) value{};
-        return value++;
-    }
-
-public:
-    /*! @brief Unsigned integer type. */
-    using value_type = id_type;
-
-    /*! @brief Statically generated unique identifier for the given type. */
-    template<typename... Type>
-    // at the time I'm writing, clang crashes during compilation if auto is used instead of value_type
-    inline static const value_type value = identifier();
-};
-
-} // namespace entt
-
-#endif