chore: update license and solidity version in interfaces

Author: johnletey

src/interfaces/IRegistrar.sol

@@ -1,5 +1,5 @@
-// SPDX-License-Identifier: Apache-2.0
-pragma solidity >=0.8.0 <0.9.0;
+// SPDX-License-Identifier: MIT OR Apache-2.0
+pragma solidity >=0.8.13 <0.9.0;
 
 /// @title IRegistrar
 /// @notice Interface for the Registrar contract.

src/interfaces/IValidatorManager.sol

@@ -1,5 +1,5 @@
-// SPDX-License-Identifier: Apache-2.0
-pragma solidity >=0.8.0 <0.9.0;
+// SPDX-License-Identifier: MIT OR Apache-2.0
+pragma solidity >=0.8.13 <0.9.0;
 
 /// @title IValidatorManager
 /// @notice Interface for the Validator Manager contract.