[fix][ml] Fix unfinished callback when deleting managed ledger (#21530)

managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/ManagedLedgerFactoryImpl.java

@@ -848,7 +848,10 @@ public void asyncDelete(String name, DeleteLedgerCallback callback, Object ctx)
                 // If it's open, delete in the normal way
                 ml.asyncDelete(callback, ctx);
             }).exceptionally(ex -> {
-                // If it's failing to get open, just delete from metadata
+                // If it fails to get open, it will be cleaned by managed ledger opening error handling.
+                // then retry will go to `future=null` branch.
+                final Throwable rc = FutureUtil.unwrapCompletionException(ex);
+                callback.deleteLedgerFailed(getManagedLedgerException(rc), ctx);
                 return null;
             });
         }