remove unused code

Author: jesseposner

Diff for: src/modules/frost/keygen_impl.h

@@ -238,12 +238,6 @@ typedef struct {
     size_t threshold;
 } secp256k1_frost_compute_pubshare_ecmult_data;
 
-typedef struct {
-    const secp256k1_context *ctx;
-    const secp256k1_pubkey * const* pks;
-    size_t threshold;
-} secp256k1_frost_pubkey_combine_ecmult_data;
-
 typedef struct {
     const secp256k1_context *ctx;
     const secp256k1_pubkey * const* pubshares;