Increase block validation timeouts (#4156)

* Increase UTXO lookup timeout

Avoid block validation failures because UTXOs aren't available on time.

* Increase the block verification timeout

Attempt to reduce the synchronization restarts and consequently improve
performance.

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

zebra-consensus/src/transaction.rs

@@ -51,7 +51,7 @@ mod tests;
 ///     to download, because a peer sent Zebra a bad list of block hashes. (The
 ///     UTXO verification failure will restart the sync, and re-download the
 ///     chain in the correct order.)
-const UTXO_LOOKUP_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(3 * 60);
+const UTXO_LOOKUP_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(6 * 60);
 
 /// Asynchronous transaction verification.
 ///

zebrad/src/components/sync.rs

@@ -141,7 +141,7 @@ pub(super) const BLOCK_DOWNLOAD_TIMEOUT: Duration = Duration::from_secs(15);
 ///
 /// If this timeout is set too low, the syncer will sometimes get stuck in a
 /// failure loop.
-pub(super) const BLOCK_VERIFY_TIMEOUT: Duration = Duration::from_secs(180);
+pub(super) const BLOCK_VERIFY_TIMEOUT: Duration = Duration::from_secs(6 * 60);
 
 /// Controls how long we wait to restart syncing after finishing a sync run.
 ///