Update ecRecover to Recognize Private Key Deactivation

EIP-7851 highlights that immutable ERC-20 contracts with ERC-2612 permit, like DAI, and Uniswap Permit2 use ecRecover precompile for signature checks. After key deactivation, these contracts remain unaware of invalid keys. Proposed standalone EIP updates ecRecover to recognize key deactivation. It excludes pure-Solidity ECDSA verification. @nconsigny supports separating this from EIP-7851 for clarity.