build: remove entt library

include/entt/stl/cstdint.hpp

@@ -1,21 +0,0 @@
-#ifndef ENTT_STL_CSTDINT_HPP
-#define ENTT_STL_CSTDINT_HPP
-
-/*! @cond ENTT_INTERNAL */
-#if __has_include(<entt/ext/stl/cstdint.hpp>)
-#    include <entt/ext/stl/cstdint.hpp>
-#else
-#    include <cstdint>
-
-namespace entt::stl {
-
-using std::uint16_t;
-using std::uint32_t;
-using std::uint64_t;
-using std::uint8_t;
-
-} // namespace entt::stl
-#endif
-/*! @endcond */
-
-#endif