[Sync EN] Document IntlDateFormatter::parseToCalendar and Spoofchecker::setAllowedChars (PHP 8.4) (#5283)

[github-actions]

Commit: https://github.com/php/doc-en/commit/20687bf9c58232244e41272d118b98ef4af16a69
PR: https://github.com/php/doc-en/pull/5283

Neue EN-Dateien (noch nicht übersetzt)

• reference/intl/dateformatter/parsetocalendar.xml
• reference/intl/spoofchecker/setallowedchars.xml