Avoid another copy of key schedule pointer in PROV_GCM_CTX

Avoid another copy of key schedule pointer in PROV_GCM_CTX

This copy would need an update on dupctx but
rather than doing it just remove the copy.

This fixes failures of evp_test on Windows with
new CPUs.

Fixes #24135

(cherry picked from commit 143ca66cf00c88950d689a8aa0c89888052669f4)

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Reviewed-by: Tom Cosgrove <tom.cosgrove@arm.com>
Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/24565)