fix(test): BackwardSyncAlgSpec slightly increase timeout to pass it i…

…n CI

Signed-off-by: Usman Saleem <usman@usmans.info>

ethereum/eth/src/test/java/org/hyperledger/besu/ethereum/eth/sync/backwardsync/BackwardSyncAlgSpec.java

@@ -189,7 +189,7 @@ public void shouldAwokeWhenConditionReachedAndReady() throws Exception {
 
     completionCaptor.getValue().onInitialSyncCompleted();
 
-    voidCompletableFuture.get(500, TimeUnit.MILLISECONDS);
+    voidCompletableFuture.get(800, TimeUnit.MILLISECONDS);
     assertThat(voidCompletableFuture).isCompleted();
 
     verify(context.getSyncState()).unsubscribeTTDReached(88L);