Function solana_vote_program::vote_state::update_validator_identity

pub fn update_validator_identity<S: BuildHasher>(
    invoke_context: &InvokeContext<'_>, 
    instruction_context: &InstructionContext, 
    signers: &HashSet<Pubkey, S>, 
    vote_account_index: usize, 
    node_pubkey: &Pubkey
) -> Result<(), InstructionError>

Update the node_pubkey, requires signature of the authorized voter