fix(replication): abandon purges to targets the bucket no longer names

A permanent version delete whose replication keeps failing stays in
xl.meta as a PENDING purge, hidden from listings, until every target
confirms it. Once the operator removes the replication configuration or
the rule naming that target nothing ever confirms it: the heal path
derived its delete decision from the configuration (the decision string
is not persisted) and skipped the version forever, so DeleteBucket
answered BucketNotEmpty for a residue the client could neither list nor
remove (rustfs/backlog#2340).

Owe a version purge to the targets its purge state names, let the heal
path through without a configuration, and have the delete worker settle
a target the configuration no longer names as abandoned: the purge is
reported complete locally through the normal writeback, the replica on
the former target is left alone, and the event
replication_purge_abandoned plus a counter are the record.

crates/scanner/src/scanner_folder/item_actions.rs

@@ -1036,12 +1036,19 @@ impl ScannerItem {
             return;
         }
 
-        let Some(replication) = self.replication.clone() else {
-            return;
+        let replication = match self.replication.clone() {
+            Some(replication) => (*replication).clone(),
+            // No active rules or targets, but a purge the bucket still owes
+            // must reach the heal path: the delete worker settles it against
+            // the current configuration (abandoned when the target is gone,
+            // rustfs/backlog#2340) so the hidden version stops blocking
+            // DeleteBucket.
+            None if !oi.version_purge_status.is_empty() => ReplicationConfig::new(None, None),
+            None => return,
         };
 
         let done_replication = Metrics::time(Metric::CheckReplication);
-        let replication_result = queue_replication_heal(&oi.bucket, oi.clone(), (*replication).clone(), 0).await;
+        let replication_result = queue_replication_heal(&oi.bucket, oi.clone(), replication, 0).await;
         done_replication();
         let roi = replication_result.object_info;
         record_scanner_replication_admission(global_metrics(), &roi, replication_result.admission);