Rename mldsa _key_from_pkey functions to include variant name (#14590)

Rename private_key_from_pkey -> mldsa65_private_key_from_pkey and
public_key_from_pkey -> mldsa65_public_key_from_pkey to match the
naming convention established for other mldsa barrier functions.

https://claude.ai/code/session_014t7oCq48f3U1MDG1rBzmcU

Co-authored-by: Claude <noreply@anthropic.com>

Author: alex

src/rust/src/backend/keys.rs

@@ -174,7 +174,7 @@ fn private_key_from_pkey<'p>(
                 pub_len,
                 cryptography_openssl::mldsa::MlDsaVariant::MlDsa65.public_key_bytes()
             );
-            Ok(crate::backend::mldsa::private_key_from_pkey(pkey)
+            Ok(crate::backend::mldsa::mldsa65_private_key_from_pkey(pkey)
                 .into_pyobject(py)?
                 .into_any())
         }
@@ -312,7 +312,7 @@ fn public_key_from_pkey<'p>(
                 pub_len,
                 cryptography_openssl::mldsa::MlDsaVariant::MlDsa65.public_key_bytes()
             );
-            Ok(crate::backend::mldsa::public_key_from_pkey(pkey)
+            Ok(crate::backend::mldsa::mldsa65_public_key_from_pkey(pkey)
                 .into_pyobject(py)?
                 .into_any())
         }

src/rust/src/backend/mldsa.rs

@@ -22,15 +22,15 @@ pub(crate) struct MlDsa65PublicKey {
     pkey: openssl::pkey::PKey<openssl::pkey::Public>,
 }
 
-pub(crate) fn private_key_from_pkey(
+pub(crate) fn mldsa65_private_key_from_pkey(
     pkey: &openssl::pkey::PKeyRef<openssl::pkey::Private>,
 ) -> MlDsa65PrivateKey {
     MlDsa65PrivateKey {
         pkey: pkey.to_owned(),
     }
 }
 
-pub(crate) fn public_key_from_pkey(
+pub(crate) fn mldsa65_public_key_from_pkey(
     pkey: &openssl::pkey::PKeyRef<openssl::pkey::Public>,
 ) -> MlDsa65PublicKey {
     MlDsa65PublicKey {