In the GitHub Actions workflow for rust-openssl testing, apply the
patch used in OpenBSD ports to support EVP_PKEY_get1_* APIs with
const_ptr. This ensures that the build succeeds before the official
version bump to libressl420.
This is a temporary workaround to keep the tests passing until
4.2.0 release.
Fix https://github.com/libressl/portable/issues/1187
Actions have been issuing annoying warnings about ubuntu-24.04 becoming
the default for ubuntu-latest for some definition of "soon". Let's see
if we care.