minor #18494 [Security] Remove {username} occurrence (alexandre-daubois)

This PR was merged into the 7.0 branch.

Discussion
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[Security] Remove `{username}` occurrence

Fix #18490

Commits
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fc0b899 [Security] Remove `{username}` occurrence

Author: javiereguiluz

security/ldap.rst

@@ -290,11 +290,6 @@ string will be replaced by the value of the ``uid_key`` configuration value
 (by default, ``sAMAccountName``), and the ``{user_identifier}`` string will be
 replaced by the user identified you are trying to load.
 
-.. deprecated:: 6.2
-
-    Starting from Symfony 6.2, the ``{username}`` string was deprecated in favor
-    of ``{user_identifier}``.
-
 For example, with a ``uid_key`` of ``uid``, and if you are trying to
 load the user ``fabpot``, the final string will be: ``(uid=fabpot)``.