FreeBSD 15.0 support

[evverx]

It was announced in https://www.freebsd.org/releases/15.0R/announce/.

It would be great if the action supported it so that it could be added to the matrix to catch things like avahi/avahi#788 automatically.

[jacob-carlborg]

Already working on it.

[arrowd]

Thank you, this will also help SSSD CI a lot.

[evverx]

FWIW I pointed the avahi CI to https://github.com/cross-platform-actions/action/tree/freebsd-15.0 and avahi failed under Valgrind with avahi/avahi@6977fab reverted due to avahi/avahi#788 as expected in https://github.com/evverx/avahi/actions/runs/20006336863/job/57369134113 so it seems to be working.