[Sync EN] Document privateKey parameter in PharData::setSignatureAlgorithm (#5229)

[github-actions]

Commit: https://github.com/php/doc-en/commit/2cbc37d710751c33862709e622d0e928c9015c45
PR: https://github.com/php/doc-en/pull/5229

Archivos ES a actualizar

• reference/phar/Phar/setSignatureAlgorithm.xml
• reference/phar/PharData/setSignatureAlgorithm.xml