Without the change build fails in `master` as
https://hydra.nixos.org/build/247669747:
In file included from /build/source/include/reactphysics3d/engine/Entity.h:30,
from /build/source/include/reactphysics3d/body/CollisionBody.h:31,
from /build/source/src/body/CollisionBody.cpp:27:
/build/source/include/reactphysics3d/configuration.h:68:19: error: 'int8_t' in namespace 'std' does not name a type; did you mean 'wint_t'?
68 | using int8 = std::int8_t;
| ^~~~~~
| wint_t