[Sync EN] Document clamp function for PHP 8.6 (#4814)

[github-actions]

Commit: https://github.com/php/doc-en/commit/bc21afc0cf0e58f48e5351fd9d5d86a0ddd71c8a
PR: https://github.com/php/doc-en/pull/4814

Nuevos archivos EN (aún no traducidos)

• reference/math/functions/clamp.xml