[LOGGING] Add logging for fail to confirm pivot block error (#7110)

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/sync/fastsync/SyncTargetManager.java

@@ -147,7 +147,11 @@ public class SyncTargetManager extends AbstractSyncTargetManager {
             })
         .exceptionally(
             error -> {
-              LOG.debug("Could not confirm best peer had pivot block", error);
+              LOG.debug(
+                  "Could not confirm best peer {} had pivot block {}",
+                  bestPeer.getLoggableId(),
+                  pivotBlockHeader.getNumber(),
+                  error);
               return Optional.empty();
             });
   }