Fix cross-version compatibility in RFC7919 changes

Fix cross-version compatibility in RFC7919 changes

- Older versions of, e.g., the FIPS provider report the minimum
  TLS version of the FFDHE groups as TLS 1.3, but we now need to
  support these in TLS 1.2.

- Older OpenSSL runtimes may not be prepared to support the FFDHE groups
  in TLS 1.2.

Therefore, instead of changing the default and FIPS providers to
advertise these groups as TLS 1.2 compatible, leave the capabilities
unchanged, and instead adjust the min(d)tls value when processing the
provider's capabilities in the new runtime.

This ensures cross-compatibility with everything except previous master
branch dev snapshots, but that's not a concern.

Fixes: #29958
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Neil Horman <nhorman@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
MergeDate: Mon Feb  9 08:53:54 2026
(Merged from https://github.com/openssl/openssl/pull/29962)