[openssl/openssl] 4e7823: `EVP_PKEY_CTX_dup` segmentation fault fix

[afshinpir]

  Branch: refs/heads/openssl-3.0
  Home:   https://github.com/openssl/openssl
  Commit: 4e782301440926eac4182540b704ddd708c707db
      https://github.com/openssl/openssl/commit/4e782301440926eac4182540b704ddd708c707db
  Author: afshinpir <afshinpir at users.noreply.github.com>
  Date:   2023-03-27 (Mon, 27 Mar 2023)

  Changed paths:
    M crypto/evp/pmeth_lib.c

  Log Message:
  -----------
  `EVP_PKEY_CTX_dup` segmentation fault fix

CLA: trivial
The the provider, context duplication method for signature, key
exchange, asymmetric cipher, and key encapsulation is optional. But if
they are missing, we will get a segmentation fault in `EVP_PKEY_CTX_dup`
because they are called without null pointer checking.

Reviewed-by: Paul Dale <pauli at openssl.org>
Reviewed-by: Shane Lontis <shane.lontis at oracle.com>
Reviewed-by: Tomas Mraz <tomas at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20581)

(cherry picked from commit 864c70e43ea5f1d7fe20bfea457e53e79fd46b6e)