patch 8.2.4853: CI with FreeBSD is a bit outdated

Problem:    CI with FreeBSD is a bit outdated.
Solution:   Use 12.3 instead of 12.1. (closes #10333)

.cirrus.yml

@@ -6,9 +6,10 @@ freebsd_12_task:
   only_if: $CIRRUS_TAG == ''
   timeout_in: 20m
   freebsd_instance:
-    image: freebsd-12-1-release-amd64
+    image: freebsd-12-3-release-amd64
   install_script:
-    pkg install -y gettext
+    - pkg update -f
+    - pkg install -y gettext
   build_script:
     - NPROC=$(getconf _NPROCESSORS_ONLN)
     - ./configure --with-features=${FEATURES}

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4853,
 /**/
     4852,
 /**/