fix ci freebsd image in cirrus ci

Author: jiegec

.cirrus.yml

@@ -2,9 +2,9 @@ task:
   freebsd_instance:
     cpu: 1
     matrix:
-      - image_family: freebsd-14-0-snap
-      - image_family: freebsd-13-1
-      - image_family: freebsd-12-3
+      - image_family: freebsd-15-0-snap
+      - image_family: freebsd-14-0
+      - image_family: freebsd-13-2
   install_script: pkg install -y bash git autoconf automake libtool groff pkgconf
   build_script:
     - ./Configure -n freebsd