minor #21152 remove documentation for the hide_user_not_found_option (xabbuh)

This PR was merged into the 8.0 branch.

Discussion
----------

remove documentation for the hide_user_not_found_option

fixes #21150

Commits
-------

1fdd7c1 remove documentation for the hide_user_not_found_option

Author: javiereguiluz

reference/configuration/security.rst

@@ -23,7 +23,6 @@ key in your application configuration.
 
 * `access_denied_url`_
 * `expose_security_errors`_
-* `hide_user_not_found`_ (deprecated)
 * `session_fixation_strategy`_
 
 **Advanced Options**:
@@ -64,24 +63,6 @@ option can be one of the following:
   accounts) but only for users who provided the correct password;
 * ``'all'``: shows all security-related exceptions.
 
-hide_user_not_found
--------------------
-
-**type**: ``boolean`` **default**: ``true``
-
-.. deprecated:: 7.3
-
-    The ``hide_user_not_found`` option was deprecated in favor of the
-    ``expose_security_errors`` option in Symfony 7.3.
-
-If ``true``, when a user is not found a generic exception of type
-:class:`Symfony\\Component\\Security\\Core\\Exception\\BadCredentialsException`
-is thrown with the message "Bad credentials".
-
-If ``false``, the exception thrown is of type
-:class:`Symfony\\Component\\Security\\Core\\Exception\\UserNotFoundException`
-and it includes the given not found user identifier.
-
 session_fixation_strategy
 -------------------------