This defines TLS1_3_VERSION when using LibreSSL 3.2+. LibreSSL 3.2/3.3
doesn't advertise this by default, even though it will use TLS 1.3
in both client and server modes.
Changes between LibreSSL 3.1 and 3.2/3.3 broke a few tests, Defining
TLS1_3_VERSION by itself fixes 1 test failure. A few tests now
fail on LibreSSL 3.2/3.3 unless TLS 1.2 is set as the maximum version,
and this adjusts those tests. The client CA test doesn't work in
LibreSSL 3.2+, so I've marked that as pending.
For the hostname verification, LibreSSL 3.2.2+ has a new stricter
hostname verifier that doesn't like subjectAltName such as
c*.example.com and d.*.example.com, so adjust the related tests.
With these changes, the tests pass on LibreSSL 3.2/3.3.
https://github.com/ruby/openssl/commit/a0e98d48c9