Release the drbg in the global default context before engines

Fixes #17995
Fixes #18578

Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/19386)

(cherry picked from commit a88e97fc)