Rename KeypairUtil to Signer (#8360)

automerge

runtime/tests/noop.rs

@@ -2,8 +2,7 @@ use solana_runtime::{
     bank::Bank, bank_client::BankClient, loader_utils::create_invoke_instruction,
 };
 use solana_sdk::{
-    client::SyncClient, genesis_config::create_genesis_config, pubkey::Pubkey,
-    signature::KeypairUtil,
+    client::SyncClient, genesis_config::create_genesis_config, pubkey::Pubkey, signature::Signer,
 };
 
 #[test]

runtime/tests/stake.rs

@@ -8,7 +8,7 @@ use solana_sdk::{
     client::SyncClient,
     message::Message,
     pubkey::Pubkey,
-    signature::{Keypair, KeypairUtil},
+    signature::{Keypair, Signer},
     system_instruction::create_address_with_seed,
     sysvar::{self, stake_history::StakeHistory, Sysvar},
 };

runtime/tests/storage.rs

@@ -13,7 +13,7 @@ use solana_sdk::{
     hash::{hash, Hash},
     message::Message,
     pubkey::Pubkey,
-    signature::{Keypair, KeypairUtil, Signature},
+    signature::{Keypair, Signature, Signer},
     system_instruction,
     sysvar::{
         rewards::{self, Rewards},