Merge pull request #4521 from ethereum-optimism/fix/ctp-test-contract-versions

contracts-periphery: update version on test contracts

packages/contracts-periphery/contracts/testing/helpers/CallRecorder.sol

 // SPDX-License-Identifier: MIT
-pragma solidity 0.8.15;
+pragma solidity ^0.8.0;
 
 contract CallRecorder {
     struct CallInfo {

packages/contracts-periphery/contracts/testing/helpers/ExternalContractCompiler.sol

 // SPDX-License-Identifier: MIT
-pragma solidity 0.8.15;
+pragma solidity ^0.8.0;
 
 import { ProxyAdmin } from "@eth-optimism/contracts-bedrock/contracts/universal/ProxyAdmin.sol";
 import { Proxy } from "@eth-optimism/contracts-bedrock/contracts/universal/Proxy.sol";

packages/contracts-periphery/contracts/testing/helpers/FailingReceiver.sol

 // SPDX-License-Identifier: MIT
-pragma solidity 0.8.15;
+pragma solidity ^0.8.0;
 
 contract FailingReceiver {
     receive() external payable {

packages/contracts-periphery/contracts/testing/helpers/Reverter.sol

 // SPDX-License-Identifier: MIT
-pragma solidity 0.8.15;
+pragma solidity ^0.8.0;
 
 contract Reverter {
     function doRevert() public pure {

packages/contracts-periphery/contracts/testing/helpers/SimpleStorage.sol

 // SPDX-License-Identifier: MIT
-pragma solidity 0.8.15;
+pragma solidity ^0.8.0;
 
 contract SimpleStorage {
     mapping(bytes32 => bytes32) public db;

packages/contracts-periphery/contracts/testing/helpers/TestERC20.sol

 // SPDX-License-Identifier: MIT
-pragma solidity 0.8.15;
+pragma solidity ^0.8.0;
 
 import { ERC20 } from "@rari-capital/solmate/src/tokens/ERC20.sol";
 

packages/contracts-periphery/contracts/testing/helpers/TestERC721.sol

 // SPDX-License-Identifier: MIT
-pragma solidity 0.8.15;
+pragma solidity ^0.8.0;
 
 import { ERC721 } from "@rari-capital/solmate/src/tokens/ERC721.sol";