doesnt built on openbsd -current (soon 7.4)

with the following versions openssl-sys does not built on openbsd

```
% uname -a
OpenBSD openbsd-current.my.domain 7.4 GENERIC.MP#1383 amd64

% openssl version
LibreSSL 3.8.2
```

soon this will be the -stable version of 7.4 and code will no longer built then until fixed