No need to use mb functions here

When mb functions are used and a large response is given the OOM happens as mb functions will use large quantities of memory.
Merge branch '2.3' into 2.4

* 2.3:
  Little correction for case 'ar'
  No need to use mb functions here
  [HttpFoundation] update phpdoc of SessionHandlerInterface and unify parameters of all handlers according to interface
  [Doctrine Bridge] fix DbalSessionHandler for high concurrency, interface compliance, compatibility with all drivers (oci8, mysqli, pdo with mysql, sqlsrv, sqlite)
  [Finder] Marked test skipped when ftp stream wrapper is not available