CI: cirrus: switch to FreeBSD-13.0

we use outdated FreeBSD-12.2, which is outdated, let us update
to the actual release

(cherry picked from commit 9902bf266c4856c35e81ff2cbed89732d750c209)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 07bb43b0c2134014e623ecb4d8f9d3a942b976c1)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/.cirrus.yml b/.cirrus.yml
index fdabfdc..e754f83 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -1,7 +1,7 @@
 FreeBSD_task:
   freebsd_instance:
     matrix:
-      image_family: freebsd-12-2
+      image_family: freebsd-13-0
   only_if: $CIRRUS_BRANCH =~ 'master|next'
   install_script:
     - pkg update -f && pkg upgrade -y && pkg install -y openssl git gmake lua53 socat pcre