[php-src] PR #25398: ext/openssl: Fix SNI certs not used on streams sharing a session SSL_CTX

Pull Request: https://github.com/php/php-src/pull/25398 Author: bukka Since b1242c32bca a server stream seeded from a session stream shares the parent's SSL_CTX and ignores its own context options. The SNI callback registered on that context looks up sni_certs of the stream doing the handshake, but the table stayed only on the parent, so the child always served the default certificate instead of the one matching the requested name. This gives the child its own table that references the parent's per-name contexts (SSL_CTX_up_ref), so it also stays valid when the parent is closed first. It follows the same approach as the ALPN list copy in GH-25211. Only 8.6 is affected. In 8.5 a server stream with a session stream still created its own context from its own options.