Remove ERC20 from core contracts (#8212)

### Description

`RegisteredContracts` list used in ContractKit for comprehensive registry lookup and governance proposal decoding (among others) errantly includes `CeloContract.ERC20` introduced in #7753 despite this not being a registered contract. This PR adds `CeloContract.ERC20` to `AuxiliaryContracts` to be filtered out.

### Tested

Before change, `Error: ERC20 not yet deployed for this chain` is emitted on many CLI changes. After change, error is no longer observed.

packages/sdk/contractkit/src/base.ts

@@ -45,6 +45,7 @@ const AuxiliaryContracts = [
   CeloContract.MultiSig,
   CeloContract.MetaTransactionWalletDeployer,
   CeloContract.MetaTransactionWallet,
+  CeloContract.ERC20,
 ]
 export const RegisteredContracts = AllContracts.filter((v) => !AuxiliaryContracts.includes(v))