Fix docs.rs documentation

[Jakuje]

The 1.5.2 documentation build failed (for all ossl, ossl-sys, kryoptic ...):

https://docs.rs/crate/ossl/latest/builds/3722007

https://docs.rs/crate/kryoptic/latest/builds/3722009

[INFO] [stderr]   cargo::rustc-check-cfg=cfg(ossl_v307,ossl_v320,ossl_v350,ossl_v400)
[INFO] [stderr]   cargo:rustc-env=OPENSSL_VERSION_NUMBER=300000d0
[INFO] [stderr]   Compile Error: "OpenSSL 3.2.0 or later is required"

We will likely need some way to build a documentation in ancient containers running openssl 3.0 ...

[simo5]

yeah we need to not require 3.2.0 for the docs for now .. which is kind of a pity :(