[Sync EN] ext/intl: Add IntlListFormatter class documentation (PHP 8.5) (#5692)

[github-actions]

Commit: https://github.com/php/doc-en/commit/e1b9f588815a51682acf68f9b8929f49ad612488
PR: https://github.com/php/doc-en/pull/5692

Neue EN-Dateien (noch nicht übersetzt)

• appendices/migration85/new-classes.xml
• reference/intl/book.xml
• reference/intl/intllistformatter.xml
• reference/intl/intllistformatter/construct.xml
• reference/intl/intllistformatter/format.xml