contracts-bedrock: fix implementation salt (#7263)

Updates the implementation salt. Without this change, the
deployments fail on Goerli. They work on the devnet so something
must be different between the devnet and the live network.
This change will ensure that there is less config to manage
in the superchain registry by having a canonical address for
each semver version.
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

packages/contracts-bedrock/scripts/Deploy.s.sol

@@ -47,7 +47,7 @@ contract Deploy is Deployer {
     /// @notice The create2 salt used for deployment of the contract implementations.
     ///         Using this helps to reduce config across networks as the implementation
     ///         addresses will be the same across networks when deployed with create2.
-    bytes32 constant IMPL_SALT = bytes32("ether's phoenix");
+    bytes32 constant IMPL_SALT = keccak256(bytes("ether's phoenix"));
 
     /// @notice The name of the script, used to ensure the right deploy artifacts
     ///         are used.