`msg.sender != tx.origin` check in `__activateTstore()` is no longer safe after EIP-7702

[MiloTruck]

__activateTstore() has the following check to avoid re-entrancy issues:

// Ensure this function is triggered from an externally-owned account.
if (msg.sender != tx.origin) {
    revert OnlyDirectCalls();
}

I believe this check is no longer safe once EIP-7702 goes live, since it becomes possible for an EOA to contain code. An EOA can call its own address, which then calls __activateTstore().

It would be safer to ensure the caller has no code instead (i.e. msg.sender.code.length == 0).