address offline comments

- The whole behavior around the negoatiated flag was rather confusing,
  but it should no longer be used, since the connection_set_test_message
method will not automatically choose a coorrect handshake type.

tests/testlib/s2n_key_schedule_testlib.c

@@ -19,7 +19,6 @@ S2N_RESULT s2n_connection_set_test_transcript_hash(struct s2n_connection *conn,
         message_type_t message_type, const struct s2n_blob *digest)
 {
     RESULT_GUARD(s2n_connection_set_test_message_type(conn, message_type));
-    conn->handshake.handshake_type &= NEGOTIATED;
     RESULT_CHECKED_MEMCPY(conn->handshake.hashes->transcript_hash_digest,
             digest->data, digest->size);
     return S2N_RESULT_OK;