Set the server sig algs before calling the session_secret_cb

Set the server sig algs before calling the session_secret_cb

Setting the server sig algs sets up the certificate "s3->tmp.valid_flags".
These are needed when calling ssl3_choose_cipher() which can happen
immediately after calling the session_secret_cb

Fixes #24213

Reviewed-by: Neil Horman <nhorman@openssl.org>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/24309)