BUILD: cirrus-ci: get rid of unstable freebsd images

the only stable available freebsd image on cirrus is 12.1
let us drop all "snap" images, they are unusable for running tests
because of being fragile
diff --git a/.cirrus.yml b/.cirrus.yml
index 86b4047..9827734 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -1,14 +1,10 @@
 FreeBSD_task:
   freebsd_instance:
     matrix:
-      image_family: freebsd-13-0-snap
-      image_family: freebsd-12-1-snap
-      image_family: freebsd-11-3-snap
+      image_family: freebsd-12-1
   only_if: $CIRRUS_BRANCH =~ 'master|next'
-  env:
-    IGNORE_OSVERSION: yes # supress package installation error on FreeBSD-13
   install_script:
-    - pkg update -f && pkg upgrade -y && pkg install -y openssl git gmake lua53 socat
+    - pkg update -f && pkg upgrade -y && pkg install -y openssl111 git gmake lua53 socat
   script:
     - git clone https://github.com/VTest/VTest.git ../vtest
     - make -C ../vtest