[Sync EN] Fix radius_get_vendor_attr return type hint (#5620)

[github-actions]

Commit: https://github.com/php/doc-en/commit/4047ef2a8b552d69909e1cee259fcad65d2510c7
PR: https://github.com/php/doc-en/pull/5620

Neue EN-Dateien (noch nicht übersetzt)

• reference/radius/functions/radius-get-vendor-attr.xml