I thought uuid-ossp was just a bunch of utilities around uuid parsing and generation. It shouldn’t need anything special from the OS.
Keep in mind, if you're using uuid-ossp rather than just relying on Postgres's built-in gen_random_uuid() function, it's very likely because you want to generate UUIDv1s instead of UUIDv4s (as they're the only two types of UUIDs that see much use.) So this functionality is pretty essential to the extension—a version of the extension without it wouldn't be worth much.