ci: drop testing for FreeBSD 12, add for FreeBSD 14

- Drop testing for FreeBSD 12 since FreeBSD 14 is available
- Add testing for FreeBSD 14

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

(cherry picked from commit 9ee99c5f)

.github/workflows/freebsd.yml

@@ -15,7 +15,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        freebsd-version: [ 12, 13 ]
+        freebsd-version: [ 13, 14 ]
         tarantool-branch:
           - 'master'
           - 'release/3.0'