cirrus: Update to FreeBSD 14.2 and 13.4.

13.4 was released a few months back and 14.2 just recently.  Older
point releases may become unavailable in gcloud in the near future.

Acked-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>

.cirrus.yml

@@ -2,8 +2,8 @@ freebsd_build_task:
 
   freebsd_instance:
     matrix:
-      image_family: freebsd-13-3-snap
-      image_family: freebsd-14-1-snap
+      image_family: freebsd-13-4-snap
+      image_family: freebsd-14-2-snap
     cpu: 4
     memory: 4G