[Tech]: Kensetsu. Unsigned liquidation check errors in log on node

[ra9mls]

Problem statement

Nodes have a lot of error messages during the unsigned checking the liquidation

Description

2024-09-16 17:18:42 (offchain call) Error submitting a transaction to the pool: Transaction pool error: Invalid transaction validity: InvalidTransaction::Custom(5)
2024-09-16 17:18:42 (offchain call) Error submitting a transaction to the pool: Transaction pool error: Invalid transaction validity: InvalidTransaction::Custom(5)
2024-09-16 17:18:42 (offchain call) Error submitting a transaction to the pool: Transaction pool error: Invalid transaction validity: InvalidTransaction::Custom(5)
2024-09-16 17:18:42 Failed in offchain_worker send liquidate(cdp_id: 144): ()

Definition of Done

Improve this logging and reduce amount of this events.

Requirements

https://t.me/c/2126324180/2761

[ra9mls]

Such messages appears because Kensetsu OCW on different nodes tries to send liquidate transaction, but only one could pass, other ones is ignored with this messages. We can investigate how to send such transactions only from block author node to avoid such log spamming on another nodes. But it's not critical and you can ignore it for now @vovac12