CI: cirrus-ci: bump FreeBSD image to 13-1

FreeBSD-13.2 released on April 11, 2023
diff --git a/.cirrus.yml b/.cirrus.yml
index e6b63e1..2993b94 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -1,7 +1,7 @@
 FreeBSD_task:
   freebsd_instance:
     matrix:
-      image_family: freebsd-13-1
+      image_family: freebsd-13-2
   only_if: $CIRRUS_BRANCH =~ 'master|next'
   install_script:
     - pkg update -f && pkg upgrade -y && pkg install -y openssl git gmake lua53 socat pcre