fix(syncer): remove duplicate notify_subscribers calls

[VolodymyrBg]

The [cache_block()]

summit/syncer/src/actor.rs

Lines 933 to 937 in ca596c1

	/// Add a notarized block to the prunable archive.
	async fn cache_block(&mut self, round: Round, commitment: B::Commitment, block: B) {
	self.notify_subscribers(commitment, &block).await;
	self.cache.put_block(round, commitment, block).await;
	}

function already calls [notify_subscribers()]

summit/syncer/src/actor.rs

Lines 828 to 834 in ca596c1

	async fn notify_subscribers(&mut self, commitment: B::Commitment, block: &B) {
	if let Some(mut bs) = self.block_subscriptions.remove(&commitment) {
	for subscriber in bs.subscribers.drain(..) {
	subscriber.send_lossy(block.clone());
	}
	}
	}

internally, so the explicit calls after it were redundant. While not a bug (the second call was a no-op since subscribers are removed on first call), this removes unnecessary BTreeMap lookups and async function calls.