minor #19658 [Ldap] Adds return value hint of LdapUser::getExtraFields() (mvhirsch)

This PR was merged into the 5.4 branch.

Discussion
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[Ldap] Adds return value hint of `LdapUser::getExtraFields()`

Hi,

I'm not sure if this is the correct approach to document that. Please advice me where to document this. I'd love to get this done correctly.

- Fixes symfony/symfony#49994
- refs symfony/symfony#49187

Commits
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f75e437 adds hint of return value

Author: javiereguiluz

security/ldap.rst

@@ -197,6 +197,12 @@ use the ``ldap`` user provider.
             ;
         };
 
+.. versionadded:: 5.4
+
+    `LdapUser::getExtraFields()` always returns an array of values. Prior
+    `LdapUserProvider` threw and `InvalidArgumentException` on multiple
+    attributes.
+
 .. caution::
 
     The Security component escapes provided input data when the LDAP user