ci: remove freebsd-13-2 task

.cirrus.yml

@@ -1,15 +1,3 @@
-task:
-  name: freebsd-13-amd64
-  freebsd_instance:
-    image_family: freebsd-13-2
-  setup_script:
-    - pkg update
-    - pkg install -y pkgconf git sdl2 python fontconfig opus
-    - git submodule update --init --recursive
-  test_script:
-    - ./scripts/cirrus/build_freebsd.sh dedicated
-    - ./scripts/cirrus/build_freebsd.sh full
-
 task:
   name: freebsd-14-amd64
   freebsd_instance: