Label Raft snapshots metrics as new

Author: NataliaIvakina

modules/ROOT/pages/monitoring/metrics/reference.adoc

@@ -478,9 +478,9 @@ label:deprecated[Deprecated in 5.15]
 |<prefix>.cluster.raft.replication_maybe|Raft Replication maybe count. (counter)
 |<prefix>.cluster.raft.replication_success|The total number of Raft replication requests that have succeeded. (counter)
 |<prefix>.cluster.raft.last_leader_message|The time elapsed since the last message from a leader in milliseconds. Should reset periodically. (gauge)
-|<prefix>.cluster.raft.snapshot_attempt|Total number of attempts to download Raft snapshots triggered. (counter)
-|<prefix>.cluster.raft.snapshot_success|Total number of successfully downloaded Raft snapshots. (counter)
-|<prefix>.cluster.raft.snapshot_fail|Total number of failed Raft snapshot download attempts. (counter)
+|<prefix>.cluster.raft.snapshot_attempt|label:new[Introduced in 2025.01] Total number of attempts to download Raft snapshots triggered. (counter)
+|<prefix>.cluster.raft.snapshot_success|label:new[Introduced in 2025.01] Total number of successfully downloaded Raft snapshots. (counter)
+|<prefix>.cluster.raft.snapshot_fail|label:new[Introduced in 2025.01] Total number of failed Raft snapshot download attempts. (counter)
 |===