fix pragma abicoder v2

Author: tailingchen

test/foundry/base/SafeOwnable.t.sol

@@ -1,4 +1,5 @@
 pragma solidity 0.7.6;
+pragma abicoder v2;
 
 import "../../../contracts/base/SafeOwnable.sol";
 import "../interface/ISafeOwnableEvent.sol";

test/foundry/helper/Constant.sol

@@ -1,4 +1,5 @@
 pragma solidity 0.7.6;
+pragma abicoder v2;
 
 import "forge-std/Test.sol";
 

test/foundry/immunefi/34300.InvalidWithdrawal.t.sol

@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 pragma solidity 0.7.6;
+pragma abicoder v2;
 
 import "forge-std/Test.sol";
 import "../../../contracts/Vault.sol";