CI: Upgrade LibreSSL versions

[junaruga]

This PR is to upgrade LibreSSL versions, adding LibreSSL 4.2.

I have a question. I couldn't find or determine the support ending date for LibreSSL 4.2.

There is the following statement about the supporting term. However, I couldn't find when the corresponding OpenBSD branch is tagged for release. Could you tell me how to check it?

https://www.libressl.org/releases.html

LibreSSL stable branches are updated for 1 year after their corresponding OpenBSD branch is tagged for release.

In the case of the LibreSSL 4.1, the 4.1.0 version was released on 30th April 2025 according to the above LibreSSL release page. But the LibreSSL 4.1.2 support date commented in the test.yml is 20256-04-28, which is not exactly the date after 1 year from the 30th April 2025 (2025-04-30).

LibreSSL 4.1.0 (Apr 30th, 2025)

[rhenium]

In the case of the LibreSSL 4.1, the 4.1.0 version was released on 30th April 2025 according to the above LibreSSL release page. But the LibreSSL 4.1.2 support date commented in the test.yml is 20256-04-28, which is not exactly the date after 1 year from the 30th April 2025 (2025-04-30).

I think I added 1 year to the date on https://www.openbsd.org/77.html, which says OpenBSD 7.7 was released on 2025-04-28. I'm not sure why they are 2 days apart, or whether "branch is tagged for release" and "released" mean the same date, but I guess this is not too important.

[junaruga]

Okay. Thanks for the explanation.

https://www.openbsd.org/77.html

OpenBSD 7.7
...
Released Apr 28, 2025. (58th OpenBSD release)
...
LibreSSL version 4.1.0

I found the following page that OpenBSD 7.8 released LibreSSL versoin 4.2.0. So, the LibreSSL 4.2 EOL could be 2026-10-22.

https://www.openbsd.org/78.html

OpenBSD 7.8
...
Released Oct 22, 2025. (59th OpenBSD release)
...
LibreSSL version 4.2.0: