Update EIP-7612: fix basicdata version byte to ensure 32-byte header

[Forostovec]

Replace bytes(0) with a single zero byte for the account header version in verkle_set_account so that the assembled basicdata is exactly 32 bytes as specified in EIP-6800. The previous construction produced 31 bytes, shifting subsequent fields by one byte and breaking the documented offsets for code_size (5:8), nonce (8:16), and balance (16:32). Using b'\x00' restores the intended layout and keeps decoding in verkle_get_account consistent with the spec and with related documentation (EIP-6800 and the newer EIP-7864), without altering any other logic.

[eth-bot]

File EIPS/eip-7612.md

Requires 1 more reviewers from @adietrichs, @gabrocheleau, @gballet, @gottfriedherold, @jlokier, @jsign, @matkt, @parithosh, @tanishqjasoria