kvserver: add logging for ranges dropped from base queue

This commit adds logging for ranges dropped from the base queue due to exceeding
max size, improving observability. The log is gated behind V(1) to avoid
verbosity on nodes with many ranges.

Author: wenyihu6

pkg/kv/kvserver/queue.go

@@ -772,7 +772,10 @@ func (bq *baseQueue) addInternal(
 	// priority element, but it would require additional bookkeeping or a linear
 	// scan.
 	if pqLen := bq.mu.priorityQ.Len(); pqLen > bq.maxSize {
-		bq.removeLocked(bq.mu.priorityQ.sl[pqLen-1])
+		replicaItemToDrop := bq.mu.priorityQ.sl[pqLen-1]
+		log.Dev.VInfof(ctx, 1, "dropping due to exceeding queue max size: priority=%0.3f, replica=%v",
+			priority, replicaItemToDrop.replicaID)
+		bq.removeLocked(replicaItemToDrop)
 	}
 	// Signal the processLoop that a replica has been added.
 	select {