change solidity versions to 0.8.0

Author: joaquim-verges

contracts/ContractDeployer.sol

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0
-pragma solidity ^0.8.11;
+pragma solidity ^0.8.0;
 
 //  ==========  External imports    ==========
 import "@openzeppelin/contracts/utils/Create2.sol";

contracts/ContractMetadataRegistry.sol

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0
-pragma solidity ^0.8.11;
+pragma solidity ^0.8.0;
 
 //  ==========  External imports    ==========
 import "@openzeppelin/contracts/utils/Multicall.sol";

contracts/ContractPublisher.sol

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0
-pragma solidity ^0.8.11;
+pragma solidity ^0.8.0;
 
 //  ==========  External imports    ==========
 import "@openzeppelin/contracts/metatx/ERC2771Context.sol";

contracts/interfaces/IContractDeployer.sol

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0
-pragma solidity ^0.8.11;
+pragma solidity ^0.8.0;
 
 interface IContractDeployer {
     /// @dev Emitted when the registry is paused.

contracts/interfaces/IContractMetadataRegistry.sol

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0
-pragma solidity ^0.8.11;
+pragma solidity ^0.8.0;
 
 interface IContractMetadataRegistry {
     /// @dev Emitted when a contract metadata is registered

contracts/interfaces/IContractPublisher.sol

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0
-pragma solidity ^0.8.11;
+pragma solidity ^0.8.0;
 
 import "@openzeppelin/contracts/utils/structs/EnumerableSet.sol";