security/libpki: Fix build with openssl3

Fixes :

• detection of OpenSSL version (a bit hacky IMHO)
• changes breaking compilation

Doesn't cover the replacement of obsoleted functions (specially the move
from engines to providers) which is way above my paygrade.

This patch has been upstream as a PR
(https://github.com/openca/libpki/pull/74).

PR: 272280
Approved by: bruno@ruomad.net (submitter is maintainer)