Update EIP-7702: Remove old note about universal cross-chain deployment

[frangio]

While it's true that EIP-7702 can commit to deploy code without commiting to fee parameters, it doesn't solve universal cross-chain deployment because the code being deployed must be specified and signed over as an address where it is already (or will be) deployed, i.e. a universal cross-chain address has to be presumed.

Alternative

An alternative change that would solve universal cross-chain deployment would be this:

 At the start of executing the transaction, after incrementing the sender's nonce, for each
 `[chain_id, address, nonce, y_parity, r, s]` tuple do the following:

 1. Verify the chain id is either 0 or the chain's current ID.
-2. `authority = ecrecover(keccak(MAGIC || rlp([chain_id, address, nonce])), y_parity, r, s]`
+2. `authority = ecrecover(keccak(MAGIC || rlp([chain_id, code_hash, nonce])), y_parity, r, s]`,
+    where `code_hash` is the keccak256 hash of the code of `address`.

However, this requires reading the code at address which so far is not done during EIP-7702 auth list validation, and pricing would need to be updated to reflect that. In practice I don't think the cost of using EIP-7702 would increase significantly because the address would also be accessed during execution of the transaction.

[eth-bot]

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[eth-bot]

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