OpenBSD build fails because of lack of EVP_add_digest()

[demonfoo]

It appears that with OpenBSD 7.5 (which uses LibreSSL 3.9.0), Net::SSLeay fails to build. After a bit of research, I've discovered that that's because LibreSSL 3.9.0 dropped support for EVP_add_digest() (and EVP_add_cipher()).

[demonfoo]

#485

I created the above PR to conditionalize the inclusion of the function such that it won't be wrapped with LibreSSL 3.9.0; running a build and make test in an OpenBSD VM resulted in no test failures.

[YellowJacketLinux]

I'm sure it's not a surprise, but I'd just like to confirm the fix in PR #485 works with the portable version of LibreSSL 3.9.2 on x86_64 GNU/Linux (Linux From Scratch 12.2-systemd)

All tests passed.

[YellowJacketLinux]

Also worth noting that IO::Socket::SSL works fine w/ all applied tests passing, as well as all other modules so far that use it, etc. when Net::SSLeay has the PR #485 patch applied, and I applied to release version of Net::SSLeay (not github pull). Seems that nothing (that I have built so far) in cpan universe needs that OpenSSL API feature, or at least doesn't test for it.