Don't restrict the ECDSA settable ctx params unnecessarily

Don't restrict the ECDSA settable ctx params unnecessarily

We just allow all possible settables all the time. Some things like the
digest name can't actually be changed in some circumstances - but we already
have checks for those things. It's still possible to pass a digest of the
same name to one that's already been set for example.

Fixes #25012

Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/25057)