fix: switch proposer_duties table primary key to slot_number

[thedevbirb]

As title says this PR changes the PRIMARY_KEY of the proposer_duties table from public_key to slot_number, and updates the logic of set_proposer_duties method of the PostgresDatabaseService accordingly.

The reason this change is needed is that, even if rare, it might occur that a validator public key is chosen twice for the next proposer duties which leads to the second record not being written on the database table because there is a conflict with the primary key. This edge case happens quite often in a devnet which has a very small validator set size compared to Mainnet.

The downstream consequence of it is that when processing a new head event inside process_head_event in the ChainEventUpdater (see below)

helix/crates/housekeeper/src/chain_event_updater.rs

Lines 151 to 175 in 3533496

	let new_duties = if event.slot % 8 == 0 {
	match self.database.get_proposer_duties().await {
	Ok(new_duties) => Some(new_duties),
	Err(err) => {
	error!(error = %err, "Failed to get proposer duties from db");
	None
	}
	}
	} else {
	None
	};
	// Update local cache if new duties were fetched.
	if let Some(new_duties) = &new_duties {
	self.proposer_duties = new_duties.clone();
	}
	// Get the next proposer duty for the new slot.
	let next_duty =
	self.proposer_duties.iter().find(|duty| duty.slot == event.slot + 1).cloned();
	let update =
	ChainUpdate::SlotUpdate(SlotUpdate { slot: event.slot, new_duties, next_duty });
	self.send_update_to_subscribers(update).await;
	}

some proposer duties are missing which might lead to next_duty to being None. The latter is then read inside the submit_block/submit_header functions throwing the error BuilderApiError::ProposerDutyNotFound incorrectly.

[0w3n-d]

We can't modify this V1 file because it will cause an error when it tries to apply it to an existing relay. Instead it will need to modify the proposer_duties table. Can you add a new file to migrations folder with the next number and modify the table there?

[thedevbirb]

We can't modify this V1 file because it will cause an error when it tries to apply it to an existing relay. Instead it will need to modify the proposer_duties table. Can you add a new file to migrations folder with the next number and modify the table there?

Sorry about that! I've seen that on the develop branch the latest migration would be V21 so I added that. I hope it's good now.